I. Life and Writings of Aristotle.—Aristotle was born 384 B. C. at Stagira, a Greek colony in Thrace. His father, Nicomachus, was a physician, and the friend of Amyntas, king of Macedonia. The former fact may have had its influence in determining the scientific direction of the son, and the latter may have procured his subsequent summons to the Macedonian court. Aristotle at a very early age lost both his parents. In his seventeenth year he came to Plato at Athens, and continued with him twenty years. On account of his indomitable zeal for study, Plato named him “the Teacher,” and said, upon comparing him with Xenocrates, that the latter required the spur, the former the bit. Among the many charges made against his character, most prominent are those of jealousy and ingratitude towards his master, but most of the anecdotes in which these charges are embodied merit little credence. It is certain that Aristotle, after the death of Plato, stood in friendly relations with Xenocrates; still, as a writer, he can hardly be absolved from a certain want of friendship and regard towards Plato and his philosophy, though all this can be explained on psychological grounds. After Plato’s death, Aristotle went with Xenocrates to Hermeas, tyrant of Atarneus, whose sister Pythias he married after Hermeas had fallen a prey to Persian violence. After the death of Pythias he is said to have married his concubine, Herpyllis, who was the mother of his son Nicomachus. In the year 343 he was called by Philip of Macedon, to take the charge of the education of his son Alexander, then thirteen years old. Both father and son honored him highly, and the latter, with royal munificence, subsequently supported him in his studies. When Alexander went to Persia, Aristotle betook himself to Athens, and taught in the Lyceum, the only gymnasium then vacant, since Xenocrates had possession of the Academy, and the Cynics of the Cynosaerges. From the shady walks pe??pat?? of the Lyceum, in which Aristotle was accustomed to walk and expound his philosophy, his school received the name of the Peripatetic. Aristotle is said to have spent his mornings with his more mature disciples, exercising them in the profoundest questions of philosophy, while his evenings were occupied with a greater number of pupils in a more general and preparatory instruction. The former investigations were called acroamatic, the latter exoteric. He abode at Athens, and taught thirteen years, and then, after the death of Alexander, whose displeasure he had incurred, he is said to have been accused by the Athenians of impiety towards the gods, and to have fled to Chalcis, in order to escape a fate similar to that of Socrates. He died in the year 322 at Chalcis, in EubÆa.

Aristotle left a vast number of writings, of which the smaller (perhaps a fourth), but unquestionably the more important portion have come down to us, though in a form which cannot be received without some scruples. The story of Strabo about the fate of the Aristotelian writings, and the injury which they suffered in a cellar at Scepsis, is confessedly a fable, or at least limited to the original manuscripts; but the fragmentary and descriptive form which many among them, and even the most important (e. g. the metaphysics) possess, the fact that scattered portions of one and the same work (e. g. the ethics) are repeatedly found in different treatises, the irregularities and striking contradictions in one and the same writing, the disagreement found in other particulars among different works, and the distinction made by Aristotle himself between acroamatic and exoterical writings, all this gives reason to believe that we have, for the most part, before us only his oral lectures written down, and subsequently edited by his scholars.

II. Universal Character and Division of the Aristotelian Philosophy.—With Plato, philosophy had been national in both its form and content, but with Aristotle, it loses its Hellenic peculiarity, and becomes universal in scope and meaning; the Platonic dialogue changes into barren prose; a rigid, artistic language takes the place of the mythical and poetical dress; the thinking which had been with Plato intuitive, is with Aristotle discursive; the immediate beholding of reason in the former, becomes reflection and conception in the latter. Turning away from the Platonic unity of all being, Aristotle prefers to direct his attention to the manifoldness of the phenomenal; he seeks the idea only in its concrete actualization, and consequently grasps the particular far more prominently in its peculiar determinateness and reciprocal differences, than in its connection with the idea. He embraces with equal interest the facts given in nature, in history, and in the inner life of man. But he ever tends toward the individual, he must ever have a fact given in order to develope his thought upon it; it is always the empirical, the actual, which solicits and guides his speculation; his whole course is a description of the facts given, and only merits the name of a philosophy because it comprehends the empirical in its totality and synthesis; because it has carried out its induction to the farthest extent. Only because he is the absolute empiricist may Aristotle be called the truly philosopher.

This character of the Aristotelian philosophy explains at the outset its encyclopedian tendency, inasmuch as every thing given in experience is equally worthy of regard and investigation. Aristotle is thus the founder of many courses of study unknown before him; he is not only the father of logic, but also of natural history, empirical psychology, and the science of natural rights.

This devotion of Aristotle to that which is given will also explain his predominant inclination towards physics, for nature is the most immediate and actual. Connected also with this is the fact that Aristotle is the first among philosophers who has given to history and its tendencies an accurate attention. The first book of the Metaphysics is also the first attempt at a history of philosophy, as his politics is the first critical history of the different states and constitutions. In both these cases he brings out his own theory only as the consequence of that which has been historically given, basing it in the former case upon the works of his predecessors, and in the latter case upon the constitutions which lie before him.

It is clear that according to this, the method of Aristotle must be a different one from that of Plato. Instead of proceeding like the latter, synthetically and dialectically, he pursues for the most part an analytic and regressive course, that is, going backward from the concrete to its ultimate ground and determination. While Plato would take his standpoint in the idea, in order to explain from this position and set in a clearer light that which is given and empirical, Aristotle on the other hand, starts with that which is given, in order to find and exhibit the idea in it. His method is, hence, induction; that is, the derivation of certain principles and maxims from a sum of given facts and phenomena; his mode of procedure is, usually, argument, a barren balancing of facts, phenomena, circumstances and possibilities. He stands out for the most part only as the thoughtful observer. Renouncing all claim to universality and necessity in his results, he is content to have brought out that which has an approximative truth, and the highest degree of probability. He often affirms that science does not simply relate to the changeless and necessary, but also to that which ordinarily takes place, that being alone excluded from its province, which is strictly accidental. Philosophy, consequently, has with him the character and worth of a reckoning of probabilities, and his mode of exhibition assumes not unfrequently only the form of a doubtful deliberation. Hence there is no trace of the Platonic ideals, hence, also, his repugnance to a glowing and poetic style in philosophy, a repugnance which, while indeed it induces in him a fixed, philosophical terminology, also frequently leads him to mistake and misrepresent the opinions of his predecessors. Hence, also, in whatever he treated, his thorough adherence to that which is actually given.

Connected in fine with the empirical character of the Aristotelian philosophizing, is the fragmentary form of his writings, and their want of a systematic division and arrangement. Proceeding always in the line of that which is given, from individual to individual, he considers every province of the actual by itself, and makes it the subject of a separate treatise; but he, for the most part, fails to indicate the lines by which the different parts hang together, and are comprehended in a systematic whole. Thus he holds up a number of co-ordinate sciences, each one of which has an independent basis, but he fails to give us the highest science which embraces them all. The principle is sometimes affirmed that all the writings follow the idea of a whole; but in their procedure there is such a want of all systematic connection, and every one of his writings is a monograph so thoroughly independent and complete in itself, that we are sometimes puzzled to know what Aristotle himself received as a part of philosophy, and what he excluded. We are never furnished with an independent scheme or outline, we rarely find definite results or summary explanations, and even the different divisions of philosophy which he gives, vary essentially from one another. At one time he divides science into theoretical and practical, at another, he adds to these two a poetical creative science, while still again he speaks of the three parts of science, ethics, physics, and logic. At one time he divides the theoretical philosophy into logic and physics, and at another into theology, mathematics, and physics. But no one of these divisions has he expressly given as the basis on which to represent his system; he himself places no value upon this method of division, and, indeed, openly declares himself opposed to it. It is, therefore, only for the sake of uniformity that we can give the preference here to the threefold division of philosophy as already adopted by Plato.

III. Logic and Metaphysics. 1. Conception and Relation of the Two.—The word metaphysics was first furnished by the Aristotelian commentators. Plato had used the term dialectics, and Aristotle had characterized the same thing as “first philosophy,” while he calls physics the “second philosophy.” The relation of this first philosophy to the other sciences Aristotle determines in the following way. Every science, he says, must have for investigation a determined province and separate form of being, but none of these sciences reaches the conception of being itself. Hence there is needed a science which should investigate that which the other sciences take up hypothetically, or through experience. This is done by the first philosophy which has to do with being as such, while the other sciences relate only to determined and concrete being. The metaphysics, which is this science of being and its primitive grounds, is the first philosophy, since it is presupposed by every other discipline. Thus, says Aristotle, if there were only a physical substance, then would physics be the first and the only philosophy, but if there be an immaterial and unmoved essence which is the ground of all being, then must there also be an antecedent, and because it is antecedent, a universal philosophy. The first ground of all being is God, whence Aristotle occasionally gives to the first philosophy the name of theology.

It is difficult to determine the relation between this first philosophy as the science of the ultimate ground of things, and that science which is ordinarily termed the logic of Aristotle, and which is exhibited in the writings bearing the name of the Organon. Aristotle himself has not accurately examined the relations of these two sciences, the reason of which is doubtless to be found in the incomplete form of the metaphysics. But since he has embraced them both under the same name of logic, since the investigation of the essence of things (VII. 17), and the doctrine of ideas (XIII. 5), are expressly called logical, since he repeatedly attempts in the Metaphysics (Book IV.), to establish the logical principle of contradiction as an absolute presupposition for all thinking and speaking and philosophizing, and employs the method of argument belonging to that science which has to do with the essence of things (III. 2. IV. 3), and since, in fine, the categories to which he had already dedicated a separate book in the Organon are also discussed again in the Metaphysics (Book V.), it follows that this much at least may be affirmed with certainty, that he would not absolutely separate the investigations of the Organon from those of the Metaphysics, and that he would not counsel the ordinary division of formal logic and metaphysics, although he has omitted to show more clearly their inner connection.

2. Logic.—The great problem both of the logical faculty and also of logic both as science and art, consists in this, viz., to form and judge of conclusions, and through conclusions to be able to establish a proof. The conclusions, however, arise from propositions, and the propositions from conceptions. According to this natural point of view, which lies in the very nature of the case, Aristotle has divided the content of the logical and dialectical doctrine contained in the different treatises of the Organon. The first treatise in the Organon is that containing the categories, a work which treats of the universal determinations of being, and gives the first attempt at an ontology. Of these categories Aristotle enumerates ten; essence, magnitude, quality, relation, the where, the when, position, habit, action, and passion. The second treatise (de interpretatione) investigates speech as the expression of thought, and discusses the doctrine of the parts of speech, propositions and judgments. The third are the analytic books, which show how conclusions may be referred back to their principles and arranged in order of their antecedence. The first Analytic contains in two books the universal doctrine of the Syllogism. Conclusions are according to their content and end either apodictic, which possess a certain and incontrovertible truth, or dialectic, which are directed toward that which may be disputed and is probable, or, finally, sophistic, which are announced deceptively as correct conclusions while they are not. The doctrine of apodictic conclusions and thus of proofs is given in the two books of the second Analytic, that of dialectic, is furnished in the eight books of the Topic, and that of sophistic in the treatise concerning “Sophistical Convictions.”

A closer statement of the Aristotelian logic would be familiar to every one, since the formal representations of this science ordinarily given, employ for the most part only the material furnished by Aristotle. Kant has remarked, that since the time of the Grecian sage, logic has made neither progress nor retrogression. Only in two points has the formal logic of our time advanced beyond that of Aristotle; first, in adding to the categorical conclusion which was the only one Aristotle had in mind, the hypothetical and disjunctive, and second, in adding the fourth to the first three figures of conclusion. But the incompleteness of the Aristotelian logic, which might be pardoned in the founder of this science, yet abides, and its thoroughly empirical method not only still continues, but has even been exalted to a principle by making the antithesis, which Aristotle did not, between the form of a thought and the content. Aristotle, in reality, only attempted to collect the logical facts in reference to the formation of propositions, and the method of conclusions; he has given in his logic only the natural history of finite thinking. However highly now we may rate the correctness of his abstraction, and the clearness with which he brings into consciousness the logical operation of the understanding, we must make equally conspicuous with this the want of all scientific derivation and foundation. The ten categories which he, as already remarked, has discussed in a separate treatise, he simply mentions, without furnishing any ground or principle for this enumeration; that there are this number of categories is only a matter of fact to him, and he even cites them differently in different writings. In the same way also he takes up the figures of the conclusion empirically; he considers them only as forms and determinations of relation of the formal thinking, and continues thus, although he allows the conclusion to stand for the only form of science within the province of the logic of the understanding. Neither in his Metaphysics nor in his Physics does he cite the rules of the formal methods of conclusion which he develops in the Organon, clearly proving that he has nowhere in his system properly elaborated either his categories or his analytic; his logical investigations do not influence generally the development of his philosophical thought, but have for the most part only the value of a preliminary scrutiny.

3. Metaphysics.—Among all the Aristotelian writings, the Metaphysics is least entitled to be called a connected whole; it is only a connection of sketches, which, though they follow a certain fundamental idea, utterly fail of an inner mediation and a perfect development. We may distinguish in it seven distinct groups. (1) Criticism of the previous philosophic systems viewed in the light of the four Aristotelian principles, Book I. (2) Positing of the apories or the philosophical preliminary questions, III. (3) The principle of contradiction, IV. (4) Definitions, V. (5) Examination of the conception of essence (??s?a) and conceivable being (the t? ?? e??a?) or the conception of matter (???), form (e?d??), and that which arises from the connection of these two (s??????), VII. VIII. (6) Potentiality and actuality, IX. (7) The Divine Spirit moving all, but itself unmoved, XII. (8) To these we may add the polemic against the Platonic doctrine of ideas and numbers, which runs through the whole Metaphysics, but is especially carried out in Books XIII. and XIV.

(1) The Aristotelian Criticism of the Platonic Doctrine of Ideas.—In Aristotle’s antagonism to the Platonic doctrine of ideas, we must seek for the specific difference between the two systems, a difference of which Aristotle avails himself of every opportunity (especially Metaph. I. and XIII.) to express. Plato had beheld every thing actual in the idea, but the idea was to him a rigid truth, which had not yet become interwoven with the life and the movement of existence. Such a view, however, had this difficulty, the idea, however little Plato would have it so, found standing over against it in independent being the phenomenal world, while it furnished no principle on which the being of the phenomenal world could be affirmed. This Aristotle recognizes and charges upon Plato, that his ideas were only “immortalized things of sense,” out of which the being and becoming of the sensible could not be explained. In order to avoid this consequence, he himself makes out an original reference of mind to phenomenon, affirming that the relation of the two is, that of the actual to the possible, or that of form to matter, and considering also mind as the absolute actuality of matter, and matter, as the potentially mind. His argument against the Platonic doctrine of ideas, Aristotle makes out in the following way.

Passing by now the fact that Plato has furnished no satisfactory proof for the objective and independent reality of ideas, and that his theory is without vindication, we may affirm in the first place that it is wholly unfruitful, since it possesses no ground of explanation for being. The ideas have no proper and independent content. To see this we need only refer to the manner in which Plato introduced them. In order to make science possible he had posited certain substances independent of the sensible, and uninfluenced by its changes. But to serve such a purpose, there was offered to him nothing other than this individual thing of sense. Hence he gave to this individual a universal form, which was with him the idea. From this it resulted, that his ideas can hardly be separated from the sensible and individual objects which participate in them. The ideal duality and the empirical duality is one and the same content. The truth of this we can readily see, whenever we gain from the adherents to the doctrine of ideas a definite statement respecting the peculiar character of their unchangeable substances, in comparison with the sensible and individual things which participate in them. The only difference between the two consists in appending per se to the names expressing the respective ideas; thus, while the individual things are e. g. man, horse, etc., the ideas are man per se, horse per se, etc. There is only this formal change for the doctrine of ideas to rest upon; the finite content is not removed, but is only characterized as perpetual. This objection, that in the doctrine of ideas we have in reality only the sensible posited as a not-sensible, and endowed with the predicate of immutability, Aristotle urges as above remarked when he calls the ideas “immortalized things of sense,” not as though they were actually something sensible and spacial, but because in them the sensible individual loses at once its individuality, and becomes a universal. He compares them in this respect with the gods of the popular and anthropomorphical religion; as these are nothing but deified men, so the ideas are only things of nature endowed with a supernatural potency, a sensible exalted to a not-sensible. This identity between the ideas and their respective individual things amounts moreover to this, that the introduction of ideas doubles the objects to be known in a burdensome manner, and without any good results. Why set up the same thing over again? Why besides the sensible twofoldness and threefoldness, affirm a twofoldness and threefoldness in the idea? The adherents of the doctrine of ideas, when they posit an idea for every class of natural things, and through this theory set up two equivalent theories of sensible and not-sensible substances, seem therefore to Aristotle like men who think they can reckon better with many numbers than with few, and who therefore go to multiplying their numbers before they begin their reckoning. Therefore again the doctrine of ideas is a tautology, and wholly unfruitful of the explanation of being, “The ideas give no aid to the knowledge of the individual things participating in them, since the ideas are not immanent in these things, but separate from them.” Equally unfruitful are the ideas when considered in reference to the arising and departing of the things of sense. They contain no principle of becoming, of movement. There is in them no causality which might bring out the event, or explain the event when it had actually happened. Themselves without motion and process, if they had any effect, it could only be that of perfect repose. True, Plato affirms in his PhÆdon that the ideas are causes both of being and becoming, but in spite of the ideas, nothing ever becomes without a moving; the ideas, by their separation from the becoming, have no such capacity to move. This indifferent relation of ideas to the actual becoming, Aristotle brings under the categories, potentiality and actuality, and farther says that the ideas are only potential, they are only bare possibility and essentiality because they are wanting in actuality.—The inner contradiction of the doctrine of ideas is in brief this, viz., that it posits an individual immediately as a universal, and at the same time pronounces the universal, the species, as numerically an individual, and also that the ideas are set up on the one side as separate individual substances, and on the other side as participant, and therefore as universal. Although the ideas as the original conceptions of species are a universal, which arise when being is fixed in existence, and the one brought out in the many, and the abiding is given a place in the changeable, yet can they not be defined as they should be according to the Platonic notion, that they are individual substances, for there can be neither definition nor derivation of an absolute individual, since even the word (and only in words is a definition possible) is in its nature a universal, and belongs also to other objects, consequently, every predicate in which I attempt to determine an individual thing cannot belong exclusively to that thing. The adherents of the doctrine of ideas, are therefore not at all in a condition to give an idea a conceivable termination; their ideas are indefinable.—In general, Plato has left the relation of the individual objects to ideas very obscure. He calls the ideas archetypes, and allows that the objects may participate in them; yet are these only poetical metaphors. How shall we represent to ourselves this “participation,” this copying of the original archetype? We seek in vain for more accurate explanations of this in Plato. It is impossible to conceive how and why matter participates in the ideas. In order to explain this, we must add to the ideas a still higher and wider principle, which contains the cause for this “participation” of objects, for without a moving principle we find no ground for “participation.” Alike above the idea (e. g. the idea of man), and the phenomenon (e. g. the individual man), there must stand a third common to both, and in which the two were united, i. e. as Aristotle was in the habit of expressing this objection, the doctrine of ideas leads to the adoption of a “third man.” The result of this Aristotelian criticism is the immanence of the universal in the individual. The method of Socrates in trying to find the universal as the essence of the individual, and to give definitions according to conception, was as correct (for no science is possible without the universal) as the theory of Plato in exalting these universal conceptions to an independent subsistence as real individual substances, was erroneous. Nothing universal, nothing which is a kind or a species, exists besides and separate from the individual; a thing and its conception cannot be separated from each other. With these principles Aristotle hardly deviated from Plato’s fundamental idea that the universal is the only true being, and the essence of individual things; it may rather be said that he has freed this idea from its original abstraction, and given it a more profound mediation with the phenomenal world. Notwithstanding his apparent contradiction to Plato, the fundamental position of Aristotle is the same as that of his master, viz., that the essence of a thing (t? t? ?st??, t? t? ?? e??a?) is known and represented in the conception; Aristotle however recognizes the universal, the conception to be as little separated from the determined phenomenon as form from matter, and essence or substance (??s?a) in its most proper sense is, according to him, only that which cannot be predicated of another, though of this other every remaining thing may be predicated; it is that which is a this (t?de t?), the individual thing and not a universal.

(2.) The four Aristotelian principles or causes, and the relation of form and matter.—From the criticism of the Platonic doctrine of ideas arose directly the groundwork of the Aristotelian system, the determinations of matter (???), and form (e?d??). Aristotle enumerates four metaphysical principles or causes: matter, form, moving cause, and end. In a house, for instance, the matter is the wood, the form is the conception of the house, the moving cause is the builder, and the end is the actual house. These four determinations of all being resolve themselves upon a closer scrutiny into the fundamental antithesis of matter and form. The conception of the moving cause is involved with the two other ideal principles of form and of end. The moving cause is that which has secured the transition of the incomplete actuality or potentiality to the complete actuality, or induces the becoming of matter to form. But in every movement of the incomplete to the complete, the latter antedates in conception this movement, and is its motive. The moving cause of matter is therefore form. So is man the moving and producing cause of man; the form of the statue in the understanding of the artist is the cause of the movement by which the statue is produced; health must be in the thought of the physician before it can become the moving cause of convalescence; so in a certain degree is medicine, health, and the art of building the form of the house. But in the same way, the moving or first cause is also identical with the final cause or end, for the end is the motive for all becoming and movement. The moving cause of the house is the builder, but the moving cause of the builder is the end to be attained, i. e. the house. From such examples as these it is seen that the determinations of form and end may be considered under one, in so far as both are united in the conception of actuality (?????e?a), for the end of every thing is its completed being, its conception or its form, the bringing out into complete actuality that which was potentially contained in it. The end of the hand is its conception, the end of the seed is the tree, which is at the same time the essence of the seed. The only fundamental determinations, therefore, which cannot be wholly resolved into each other, are matter and form.

Matter when abstracted from form in thought, Aristotle regarded as that which was entirely without predicate, determination and distinction. It is that abiding thing which lies at the basis of all becoming; but which in its own being is different from every thing which has become. It is capable of the widest diversity of forms, but is itself without determinate form; it is every thing in possibility, but nothing in actuality. There is a first matter which lies at the basis of every determinate thing, precisely as the wood is related to the bench and the marble to the statue. With this conception of matter Aristotle prides himself upon having conquered the difficulty so frequently urged of explaining the possibility that any thing can become, since being can neither come out of being nor out of not-being. For it is not out of not-being absolutely, but only out of that which as to actuality is not-being, but which potentially is being, that any thing becomes. Possible or potential being is no more not-being than actuality. Every existing object of nature is hence but a potential thing which has become actualized. Matter is thus a far more positive substratum with Aristotle than with Plato, who had treated it as absolutely not-being. From this is clearly seen how Aristotle could apprehend matter in opposition to form as something positively negative and antithetic to the form, and as its positive denial (st???s??).

As matter coalesces with potentiality, so does form coincide with actuality. It is that which makes a distinguishable and actual object, a this (t?de t?) out of the undistinguished and in determinate matter; it is the peculiar virtue, the completed activity, the soul of every thing. That which Aristotle calls form, therefore, is not to be confounded with what we perhaps may call shape; a hand severed from the arm, for instance, has still the outward shape of a hand, but according to the Aristotelian apprehension, it is only a hand now as to matter and not as to form: an actual hand, a hand as to form, is only that which can do the proper work of a hand. Pure form is that which, in truth, is without matter (t? t? ?? e??a?); or, in other words, the conception of being, the pure conception. But such pure form does not exist in the realm of determined being; every determined being, every individual substance (??s?a), every thing which is a this, is rather a totality of matter and form, a (s??????). It is, therefore, owing to matter, that being is not pure form and pure conception; matter is the ground of the becoming, the manifold, and the accidental; and it is this, also, which gives to science its limits. For in precisely the measure in which the individual thing bears in itself a material element is it uncognizable. From what has been said, it follows that the opposition between matter and form is a variable one, that being matter in one respect which in another is form; building-wood, e. g. is matter in relation to the completed house, but in relation to the unhewn tree it is form; the soul in respect to the body is form, but in respect to the reason, which is the form of form (e?d?? e?d???) is it matter. On this standpoint the totality of all existence may be represented as a ladder, whose lowest step is a prime matter (p??t? ???), which is not at all form, and whose highest step is an ultimate form which is not at all matter, but is pure form (the absolute, divine spirit). That which stands between these two points is in one respect matter, and in another respect form, i. e. the former is ever translating itself into the latter. This position, which lies at the basis of the Aristotelian view of nature, is attained analytically through the observation that all nature exhibits the perpetual and progressive transition of matter into form, and shows the exhaustless and original ground of things as it comes to view in ever ascending ideal formations. That all matter should become form, and all that is potential should be actual, and all that is should be known, is doubtless the demand of the reason and the end of all becoming; yet is this actually impracticable, since Aristotle expressly affirms that matter as the antithesis, or denial of form, can never become wholly actualized, and therefore can never be perfectly known. The Aristotelian system ends thus like its predecessors, in the unsubdued dualism of matter and form.

(3.) Potentiality and Actuality (d??a?? and ?????e?a).—The relation of matter to form, logically apprehended, is but the relation of potentiality to actuality. These terms, which Aristotle first employed according to their philosophical significance, are very characteristic for his system. We have in the movement of potential being to actual being the explicit conception of becoming, and in the four principles we have a distribution of this conception in its parts. The Aristotelian system is consequently a system of the becoming, in which the Heraclitic principle appears again in a richer and profounder apprehension, as that of the Eleatics had done with Plato. Aristotle in this has made no insignificant step towards the subjection of the Platonic dualism. If matter is the possibility of form, or reason becoming, then is the opposition between the idea and the phenomenal world potentially overcome, at least in principle, since there is one being which appears both in matter and form only in different stages of development. The relation of the potential to the actual Aristotle exhibits by the relation of the unfinished to the finished work, of the unemployed carpenter to the one at work upon his building, of the individual asleep to him awake. Potentially the seed-corn is the tree, but the grown up tree is it actually; the potential philosopher is he who is not at this moment in a philosophizing condition; even before the battle the better general is the potential conqueror; potentially is space infinitely divisible; in fact every thing is potentially which possesses a principle of motion, of development, or of change, and which, if unhindered by any thing external, will be of itself. Actuality or entelechy on the other hand indicates the perfect act, the end as gained, the completely actual (the grown-up tree e.g. is the entelechy of the seed-corn), that activity in which the act and the completeness of the act fall together, e. g. to see, to think where he sees and he has seen, he thinks and he has thought (the acting and the completeness of the act) are one and the same, while in those activities which involve a becoming, e. g. to learn, to go, to become well, the two are separated. In this apprehension of form (or idea) as actuality or entelechy, i. e. in joining it with the movement of the becoming, is found the chief antagonism of the Aristotelian and Platonic systems. Plato considers the idea as being at rest, and consisting for itself, in opposition to the becoming and to motion; but with Aristotle the idea is the eternal product of the becoming, it is an eternal energy, i. e. an activity in complete actuality, it is not perfect being, but is being produced in every moment and eternally, through the movement of the potential to its actual end.

(4.) The Absolute, Divine Spirit.—Aristotle has sought to establish from a number of sides, the conception of the absolute spirit, or as he calls it, the first mover, and especially by joining it to the relation of potentiality and actuality.

(a.) The Cosmological Form.—The actual is ever antecedent to the potential not only in conception (for I can speak of potentiality only in reference to some activity) but also in time, for the acting becomes actual only through an acting; the uneducated becomes educated through the educated, and this leads to the claim of a first mover which shall be pure activity. Or, again, it is only possible that there should be motion, becoming, or a chain of causes, except as a principle of motion, a mover exists. But this principle of motion must be one whose essence is actuality, since that which only exists in possibility cannot alone become actual, and therefore cannot be a principle of motion. All becoming postulates with itself that which is eternal and which has not become, that which itself unmoved is a principle of motion, a first mover.

(b.) The Ontological Form.—In the same way it follows from the conception of potentiality, that the eternal and necessary being cannot be potential. For that which potentially is, may just as well either be or not be; but that which possibly is not, is temporal and not eternal. Nothing therefore which is absolutely permanent, is potential, but only actual. Or, again, if potentiality be the first, then can there be no possible existence, but this contradicts the conception of the absolute or that which it is impossible should not be.

(c.) The Moral Form.—Potentiality always involves a possibility to the most opposite. He who has the capacity to be well, has also the capacity to be sick, but actually no man is at the same time both sick and well. Therefore actuality is better than potentiality, and only it can belong to the eternal.

(d.) So far as the relation of potentiality and actuality is identical with the relation of matter and form, we may apprehend in the following way these arguments for the existence of a being which is pure actuality. The supposition of an absolute matter without form (the p??t? ???) involves also the supposition of an absolute form without matter (a p??t?? e?d??). And since the conception of form resolves itself into the three determinations, of the moving, the conceivable, and the final cause, so is the eternal one the absolute principle of motion (the first mover p??t?? ??????), the absolute conception or pure intelligible (the pure t? ?? e??a?) , and the absolute end.

All the other predicates of the first mover or the highest principle of the world, follow from these premises with logical necessity. Unity belongs to him, since the ground of the manifoldness of being lies in the matter and he has no participation in matter; he is immovable and abiding ever the same, since otherwise he could not be the absolute mover and the cause of all becoming; he is life as active self-end and actuality; he is at the same time intelligible and intelligence, because he is absolutely immaterial and free from nature; he is active, i. e. thinking intelligence, because his essence is pure actuality; he is self-contemplating intelligence, because the divine thought cannot attain its actuality in any thing extrinsic, and because if it were the thought of any thing other than itself, this would make it depend upon some potential existence for its actualization. Hence the famed Aristotelian definition of the absolute that it is the thought of thought (???s?? ???ae??), the personal unity of the thinking and the thought, of the knowing and the known, the absolute subject-object. In the Metaphysics (XII. 1.) we have a statement in order of these attributes of the Divine Spirit, and an almost devout sketch of the eternally blessed Deity, knowing himself in his eternal tranquillity as the absolute truth, satisfied with himself, and wanting neither in activity nor in any virtue.

As would appear from this statement, Aristotle has never fully developed the idea of his absolute spirit, and still less has he harmonized it with the fundamental principles and demands of his philosophy, although many consequences of his system would seem to drive him to this, and numerous principles which he has laid down would seem to prepare the way for it. This idea is unexpectedly introduced in the twelfth book of the Metaphysics simply as an assertion, without being farther and inductively substantiated. It is at once attended with important difficulties. We do not see why the ultimate ground of motion or the absolute spirit must be conceived as a personal being; we do not see how any thing can he a moving cause and yet itself unmoved; how it can be the origin of all becoming, that is of the departing and arising, and itself remain a changeless energy, a principle of motion with no potentiality to be moved, for the moving thing must stand in a relation of passive and active with the thing moved. Moreover, Aristotle, as would follow from these contradictory determinations, has never thoroughly and consistently determined the relation between God and the world. He has considered the absolute spirit only as contemplative and theoretical reason, from whom all action must be excluded because he is perfect end in himself, but every action presupposes an end not yet perfected; we have thus no true motive for his activity in reference to the world. He cannot be truly called the first mover in his theoretical relation alone, and since he is in his essence extra-mundane and unmoved, he cannot once permeate the life of the world with his activity; and since also matter on one side never rises wholly to form, we have, therefore, here again the unreconciled dualism between the Divine spirit and the unmistakable reality of matter. Many of the arguments which Aristotle brings against the gods of Anaxagoras may be urged against his own theory.

IV. The Aristotelian Physics.—The Aristotelian Physics, which embraces the greater portion of his writings, follows the becoming and the building up of matter into form, the course through which nature as a living being progresses in order to become individual soul. All becoming has an end; but end is form, and the absolute form is spirit. With perfect consistency, therefore, Aristotle regards the human individual of the male sex as the end and the centre of earthly nature in its realized form. All else beneath the moon is, as it were, an unsuccessful attempt of nature to produce the male human, a superfluity which arises from the impotence of nature to subdue the whole of matter and bring it into form. Every thing which does not gain the universal end of nature must be regarded as incomplete, and is properly an exception or abortion. For instance, he calls it an abortion when a child does not resemble its father; and the female child he looks upon as an abortion in a less degree, which he accounts for by the insufficient energy of the male as the forming principle. In general, Aristotle regards the female as imperfect in comparison with the male, an imperfection which belongs in a higher degree to all animals except man. If nature did her work with perfect consciousness, then were all these mistakes, these incomplete and improper formations inexplicable, but she is an artist working only after an unconscious impulse, and does not complete her work with a clear and rational insight.

1. The universal conditions of all natural existence, motion, matter, space and time, Aristotle investigates in the books of Physics. These physical conceptions may, moreover, be reduced to the metaphysical notions of potentiality and actuality; motion is accordingly defined as the activity of being potentially, and is therefore a mean between the merely potential entity and the perfectly realized activity;—space is the possibility of motion and possesses, therefore, potentially, though not actively, the property of infinite divisibility; time is in the same way the infinitely divisible, expressing the measure of motion in number, and is the number of motion according to before and after. All three are infinite, but the infinite which is represented in them is only potentially but not actually a whole: it comprehends nothing, but is itself comprehended,—a fact mistaken by those who are accustomed to extol the infinite as though it comprehended and held every thing in itself, because it had some similarity with the whole.

2. From his conception of motion Aristotle derives his view of the collective universe, as brought out in his books De CÆlo. The most perfect motion is the circular, because this is constant, uniform, and ever returning into itself. The world as a whole is therefore conditioned by the circular motion, and being a whole complete in itself, it has a spherical form. But because the motion which returns into itself is better than every other, it follows, from the same ground, that in this spherical universe the better sphere will be in the circumference where the circular motion is most perfect, and the inferior one will arrange itself around the centre of the universal sphere. The former is heaven, the latter is earth, and between the two stand the planetary spheres. Heaven, as the place of circular motion, and the scene of unchangeable order, stands nearest the first moving cause, and is under its immediate influence; it is the place where the ancients, guided by the correct tradition of a lost wisdom, have, placed the Divine abode. Its parts, the fixed stars, are passionless and eternal essences, which have attained the best end, which must be eternally conceived in a tireless activity, and which, though not clearly cognizable, are yet much more divine than man, A lower sphere, next to that of the fixed stars, is the sphere of the planets, among which, besides the five known to the ancients, he reckons the sun and the moon. This sphere stands a little removed from the greatest perfection: instead of moving directly from right to left, as do the fixed stars, the planets move in contrary directions and in oblique orbits; they serve the fixed stars, and are ruled by their motion. Lastly, the earth is in the centre of the universe, farthest removed from the first mover, and hence partaking in the smallest degree of the Divine. There are thus three kinds of being, exhibiting three stages of perfection, and necessary for the explanation of nature; first, the absolute spirit or God, an immaterial being, who, himself unmoved, produces motion; second, the super-terrestrial region of the heavens, a being which is moved and which moves, and which, though not without matter, is eternal and unchangeable, and possesses ever a circular motion; and, lastly, in the lowest course this earth, a changeful being, which has only to play the passive part of being moved.

3. Nature in a strict sense, the scene of elemental working, represents to us a constant and progressive transition of the elementary to the vegetative, and of the vegetative to the animal world. The lowest step is occupied by the inanimate bodies of nature, which are simple products of the elements mingling themselves together, and have their entelechy only in the determinate combinations of these elements, but whose energy consists only in striving after a fitting place in the universe, and in resting there so far as they reach it unhindered. But now such a mere external entelechy is not possessed by the living bodies; within them dwells a motion as organizing principle by which they attain to actuality, and which as a preserving activity develops in them towards a perfected organization,—in a word they have a soul, for a soul is the entelechy of an organic body. In plants we find the soul working only as persevering and nourishing energy: the plant has no other function than to nourish itself and to propagate its kind; among animals—where we find a progress according to the mode of their reproduction—the soul appears as sensitive; animals have sense, and are capable of locomotion; lastly, the human soul is at the same time nutritive, sensitive, and cognitive.

4. Man, as the end of all nature, embraces in himself the different steps of development in which the life of nature is exhibited. The division of the faculties of the soul must therefore be necessarily regulated, according to the division of living creatures. As the nutritive faculty is alone the property of vegetables, and sensation, of animals, while to the more perfect animals locomotion also belongs, so are these three activities also development steps of the human soul, the antecedent being the necessary condition of, and presupposed in time by, the subsequent, while the soul itself is nothing other than the union of these different activities of an organic body in one common end, as the entelechy of the organic body. The fourth step, thought or reason, which, added to the three others, constitutes the peculiarity of the human soul, forms alone an exception from the general law. It is not a simple product of the lower facilities of the soul, it does not stand related to them simply as a higher stage of development, nor simply as the soul to the body, as the end to the instrument, as actuality to possibility, as form to matter. But as pure intellectual activity, it completes itself without any mediation of a bodily organ; as the reason comes into the body from without, so is it separable from the body, and therefore has it no inner connection with the bodily functions, but is something wholly foreign in nature. True, there exists a connection between thought and sensation, for while the sensations are outwardly divided, according to the different objects of sense, yet internally they meet in one centre, as a common sense. Here they become changed into images and representations, which again become transmuted into thoughts, and so it might seem as if thought were only the result of the sensation, as if intelligence were passively determined; (here we might notice the proposition falsely ascribed to Aristotle: nihil est in intellectu quod non fuerit in sensu, and also the well-known though often misunderstood comparison of the soul with an unwritten tablet, which only implies this much, viz., that as the unwritten tablet is potentially but not actually a book, so does knowledge belong potentially though not actually to the human reason; fundamentally and radically the thought may have in itself universal conceptions, so far as it has the capacity to form them, but not actually, nor in a determined or developed form). But this passivity presupposes rather an activity; for if the thought in its actuality, in that it appears as knowledge, becomes all forms and therefore all things, then must the thought constitute itself that which it becomes, and therefore all passively determined human intelligence rests on an originally active intelligence, which exists as self-actualizing possibility and pure actuality, and which, as such, is wholly independent of the human body, and has not its entelechy in it but in itself, and is not therefore participant in the death of the body, but lives on as universal reason, eternal and immortal. The Aristotelian dualism here again appears. Manifestly this active intelligence stands related to the soul as God to nature. The two sides possess no essential relation to each other. As the Divine spirit could not enter the life of the world, so is the human spirit unable to permeate the life of sense; although it is determined as something passionless and immaterial, still must it as soul be connected with matter, and although it is pure and self-contemplative form, still it should be distinguished from the Divine spirit which is its counterpart; the want of a satisfactory mediation on the side of the human and on that of the Divine, is in these respects unmistakable.

V. The Aristotelian Ethics. 1. Relation of Ethics to Physics.—Aristotle, guided by his tendency towards the natural, has more closely connected ethics and physics than either of his predecessors, Socrates or Plato, had done. While Plato found it impossible to speak of the good in man’s moral condition, disconnected from the idea of the good in itself, Aristotle’s principal object is to determine what is good for man solely; and he supposes that the good in itself, the idea of the good, in no way facilitates the knowledge of that good, which alone is attainable in practical life. It is only the latter, the moral element in the life of men, and not the good in the great affairs of the universe, with which ethics has to do. Aristotle therefore considers the good especially in its relation to the natural condition of men, and affirms that it is the end towards which nature herself tends. Instead of viewing the moral element as something purely intellectual, he rather apprehends it as only the bloom of the physical, which here becomes spiritualized and ethical; instead of making virtue to be knowledge, he treats it as the normal perfection of the natural instinct. That man is by nature a political animal, is his fundamental proposition for the doctrine of the state.

From this connection of the ethical and the physical, arose the objections which Aristotle urged against the Socratic conception of virtue. Socrates had looked to the dialectical exclusively for the ground of all morality, and had accordingly made virtue and knowledge one. But in this, said Aristotle, the pathological element which is associated by nature with every moral act, is destroyed. It is not reason, but the circumstances and natural bias of the soul which are the first ground of virtue. There is an instinct in the soul which at first strives unconsciously after the good, which is only subsequently sought with the full moral insight. Moral virtue arises first from that which is natural. It is on this ground, also, that Aristotle combats the notion that virtue may be learned. It is not through the perfection of knowledge, but by exercise that we become acquainted with the good. It is by a practice of moral acts that we become virtuous, just as by a practice of building and of music we become architects and musicians; for the habit which is the ground of moral constancy, is only a fruit of the abundant repetition of a moral action. Hence it is that originally we have our virtuous or our vicious dispositions in our power, but as soon as they are formed either to virtue or to vice, we are no longer able to control them. It is by three things, therefore, nature, habit, and reason, that man becomes good. The standpoint of Aristotle is in these respects directly opposed to that of Socrates. While Socrates regarded the moral and the natural as two opposites, and made the moral conduct to be the consequent of a rational enlightenment, Aristotle treated both as different steps of development, and reversing the order of Socrates, made the rational enlightenment in moral things consequent upon the moral conduct.

2. The Highest Good.—Every action has an end; but since every end is only itself a means to some other, we need therefore something after which we can strive for its own sake, and which is a good absolutely, or a best. What now is this highest good and supreme object of human pursuit? In name, at least, all men are agreed upon it, and call it happiness, but what happiness is, is a much disputed point. If asked in what human happiness consists, the first characteristic given would be that it belongs alone to the peculiar being of man. But sensation is not peculiar to man, for he shares this with the brute. A sensation of pleasure, therefore, which arises when some desire is gratified, may be the happiness of the brute, but certainly does not constitute the essential of human happiness. Human happiness must express the completeness of intelligent existence, and because intelligence is essentially activity, therefore the happiness of man cannot consist in any merely passive condition, but must express a completeness of human action. Happiness therefore is a well-being, which is at the same time a well-doing, and it is a well-doing which satisfies all the conditions of nature, and which finds the highest contentment or well-being in an unrestrained energy. Activity and pleasure are thus inseparably bound together by a natural bond, and happiness is the result of their union when they are sustained through a perfect life. Hence the Aristotelian definition of happiness. It is a perfect practical activity in a perfect life.

Although it might seem from this as though Aristotle placed the happiness of man in the natural activity of the soul, and regarded this as self-sufficient, still he is not blind to the fact that perfect happiness is dependent on other kinds of good whose possession is not absolutely within our power. It is true he expresses an opinion, that outward things in moderation are sufficient, and that only great success or signal reverses materially influence the happens of life; still he holds that wealth, the possession of friends and children, noble birth, beauty of body, etc., are more or less necessary conditions of happiness, though these are partly dependent on accidental circumstances. These wavering and inconsistent views of Aristotle respecting the nature of happiness, naturally rise from his empirical method of investigation. Careful in noting every thing which our limited experience seems to utter, he expressly avoids making either virtue or pleasure his principle, because actual experience shows the separation of the two. Although therefore he gives directions in general to strive after that pleasure in which the good man delights, or which is connected with a virtuous activity, yet is pleasure with him an end for its own sake, and not merely an accident of virtue, an empiricist, Aristotle is here also a dualist, while the Stoics and Epicureans have respectively taken and held fast to each of the two sides.

3. Conception of Virtue.—As has already been seen in the Aristotelian Polemic against Socrates, virtue is the product of an oft-repeated moral action, a condition acquired through practice, a moral dexterity of the soul. The nature of this dexterity is seen in the following way: every action completes something as its work; but now if a work is imperfect when it has either a want or a superfluity, so also is every action imperfect in so far as there is in it either too little or too much; its perfection, therefore, is only found as it contains the right degree, the true mean between the too much and too little. Accordingly, virtue in general may be explained as the observation of the right mean in action, by which is meant not the arithmetical or absolute mean, but the one relative to ourselves. For what is enough for one individual is insufficient for another. The virtue of a man, of a woman, of a child, and of a slave is respectively different. Thus, virtue depends upon time, circumstance, and relation. The determination of this correct mean will always waver. In the impossibility of an active and exhaustive formula, we can only say respecting it that it is the correct mean as determined by a correct practical insight which is seen to be such by the intelligent man.

It follows from this general conception of virtue, that there will be as many separate virtues as there are circumstances of life, and as men are ever entering into new relations, in which it becomes difficult practically to determine the correct method of action, Aristotle, in opposition to Plato, would limit the field of separate virtues by no definite number. Only certain fundamental virtues can be named according as there are certain fixed and fundamental relations among men. For instance, man has a fixed relation to pleasure and pain. In relation to pain, the true moral mean is found in neither fearing nor courting it, and this is valor. In relation to pleasure, the true mean standing between greediness and indifference is temperance. In social life, the moral mean is between doing and suffering wrong, which is justice. In a similar way many other virtues might be characterized, each one of them standing as a mean between two vices, the one of which expresses a want and the other a superfluity. A closer exhibition of the Aristotelian doctrine of virtue would have much psychological and linguistic interest, though but little philosophical worth. Aristotle takes the conception of his virtues more from the use of language than from a thoroughly applied principle of classification. His classification of virtues is, therefore, without any stable ground, and is differently given in different places. The conception of the correct mean which Aristotle makes the measure of a moral act is obviously unworthy of a systematic representation, for as it cannot be determined how the intelligent man would act in every case, there could never be given any specific directions how others should act. In fine, the criterion of virtue as the correct mean between two vices cannot be always applied for in the virtue of wisdom, e. g. which Aristotle describes as the mean between simplicity and cunning, there is no such thing as too much.

4. The State.—Aristotle, like Plato, makes the highest condition of moral virtue attainable only through political life. The state exists before the individual, as the whole is prior to its parts. The rationality and morality of the state is thus antecedent to that of the individual. Hence in the best state, moral and political virtue, the virtue of the man and the virtue of the citizen are one and the same thing, although in states as they are, the good citizen is not necessarily also the good man. But though this principle harmonized with Plato, yet Aristotle, at whose time the old aboriginal states had already begun their process of dissolution, cherished a very different view concerning the relation of the individual and the family to the state. He allows to both these an incomparably greater consideration, and yields to them a far wider field of independent action. Hence he combats Plato’s community of wives and goods, not simply on the ground of its practicability, but also on the ground of its principle, since the state cannot be conceived as a strict unit, or as possessing any such centralization as would weaken or destroy individual activity. With Plato the state is but the product of the philosophical reflection, while with Aristotle it results from given circumstances, from history and experience, and he therefore wholly omits to sketch a model state or a normal constitution, but carefully confines his attention to those which actually exist. Although the ideal of a state constitution in the form of a limited monarchy is unmistakably in his mind, still he contents himself with portraying the different kinds of polities in their peculiarities, their origin, and their reciprocal transitions. He does not undertake to declare which is the best state absolutely, since this depends upon circumstances, and one constitution is not adapted for every state. He simply attempts to show what form of the state is relatively the best and the most advisable under certain historical circumstances, and under given natural, climatic, geographic, economic, and intellectual conditions. In this he is faithful to the character of his whole philosophy. Standing on the basis of the empirical, he advances here as elsewhere, critically and reflectively, and in despair of attaining the absolutely true and good, he seeks for these relatively, with his eye fixed only on the probable and the practicable.

VI.—The Peripatetic School.—The school of Aristotle, called the Peripatetic, can here only be mentioned; the want of independence in its philosophizing, and the absence of any great and universal influence, rendering it unworthy an extended notice. Theophrastus, Eudemus, and Strato are its most famous leaders. Like most philosophical schools, it confines itself chiefly to a more thorough elaboration and explanation of the system of its master. In some empirical provinces, especially the physical, the attempt was made to carry out still further the system, while at the same time its speculative basis was set aside and neglected.

VII.—Transition to the Post-aristotelian Philosophy.—The productive energy of Grecian philosophy expends itself with Aristotle, contemporaneously and in connection with the universal decay of Grecian life and spirit. Instead of the great and universal systems of a Plato and an Aristotle, we have now systems of a partial and one-sided character, corresponding to that universal breach between the subject and the objective world which characterized the civil, religious, and social life of this last epoch of Greece, the time succeeding Alexander the Great. That subjectivity, which had been first propounded by the Sophists, was at length, after numerous struggles, victorious, though its triumph was gained upon the ruins of the Grecian civil and artistic life; the individual has become emancipated, the subject is no longer to be given up to the objective world, the liberated subjectivity must now be perfected and satisfied. This process of development is seen in the post-Aristotelian philosophy, though it finds its conditioning cause in the character of the preceding philosophical strivings. The dualism which formed the chief want of the systems both of Plato and Aristotle, has forced itself upon our attention at every step. The attempt which had been made, with the greatest expenditure of which the Grecian mind was capable, to refer back to one ultimate ground both subject and object, mind and matter, had produced no satisfactory result; and these two oppositions, around which all previous philosophy had struggled in vain, still remained disconnected. Wearied with the fruitless attempts at mediation, the subject now breaks with the objective world. Its attention is directed towards itself in its own self-consciousness. The result of this gives us either STOICISM, where the moral subject appears in the self-sufficiency of the sage to whom every external good and every objective work is indifferent, and who finds a good only in a moral activity; or EPICUREANISM, where the subject delights itself in the inner feeling of pleasure and the calm repose of a satisfied heart, enjoying the present and the past, and never fearing the future while it sees in the objective world only a means by which it can utter itself; or, again, Scepticism, where the subject, doubting and rejecting all objective truth and science, appears in the apathy of the Sceptic, who has broken both theoretically and practically with the objective world. In fine, New-Platonism, the last of the ancient philosophical systems, bears this same character of subjectivity, for this whole system turns upon the exaltation of the subject to the absolute, and wherever it speculates respecting God and his relation to man, it is alone in order to establish the progressive transition from the absolute object to the human personality. The ruling principle in it all is the interest of the subjectivity, and the fact that in this system there are numerous objective determinations, is only because the subject has become absolute.