A considerable portion of the present work, comprising the whole of the first volume and the first two chapters of the second, is reprinted with corrections and additions from the Westminster Review. The last chapter of the second volume has already appeared under a slightly different title in Mind for January and April 1882. The chapters entitled, ‘The Sceptics and Eclectics,’ ‘The Religious Revival,’ and ‘The Spiritualism of Plotinus,’ are now published for the first time.

The subject of Greek philosophy is so vast that, in England at least, it has become customary to deal with it in detached portions rather than as a connected whole. This method has its advantages, but it has also its drawbacks. The critic who singles out some one thinker for special study is apt to exaggerate the importance of his hero and to credit him with the origination of principles which were really borrowed from his predecessors. Moreover, the appearance of a new idea can only be made intelligible by tracing the previous tendencies which it either continues, combines, or contradicts. In a word, the history of philosophy has itself a philosophy which requires that we should go beyond particular phenomena and view them as variously related parts of a single system.

The history of Greek philosophy, whether conceived in this comprehensive sense or as an erudite investigation into matters of detail, is a province which the Germans have made peculiarly their own; and, among German scholars, Dr. Zeller is the one who has treated it with most success. My obligations to his great work are sufficiently shown by the copious references to it which occur throughout the following pages. It is in those instances—and they are, unfortunately, very numerous—where our knowledge of particular philosophers and of their opinions rests on fragmentary or second-hand information, that I have found his assistance most valuable. This has especially been the case with reference to the pre-Socratic schools, the minor successors of Socrates, the earlier Stoics, the Sceptics, and the later Pythagoreans. I must, however, guard against the supposition that my work is, in any respect, a popularisation or abridgment of Zeller’s. To popularise Zeller would, indeed, be an impertinence, for nothing can be more luminous and interesting than his style and general mode of exposition. Nor am I playing the part of a finder to a large telescope; for my point of view by no means coincides with that of the learned German historian. Thus, while my limits have obliged me to be content with a very summary treatment of many topics which he has discussed at length, there are others, and those, in my opinion, not the least important, to which he has given less space than will be found allotted to them here. On several questions, also, I have ventured to controvert his opinions, notably with reference to the Sophists, Socrates, Aristotle, and Plotinus. My general way of looking at the Greeks and their philosophy also differs from his. And the reasons which have led me to follow an independent course in this respect involve considerations of such interest and importance, that I shall take the liberty of specifying them in some detail.

Stated briefly, Zeller’s theory of ancient thought is that the Greeks originally lived in harmony with Nature; that the bond was broken by philosophy and particularly by the philosophy of Socrates; that the discord imperfectly overcome by Plato and Aristotle revealed itself once more in the unreconciled, self-concentrated subjectivity of the later schools; that this hopeless estrangement, after reaching its climax in the mysticism of the Neo-Platonists, led to the complete collapse of independent speculation; and that the creation of a new consciousness by the advent of Christianity and of the Germanic races was necessary in order to the successful resumption of scientific enquiry. Zeller was formerly a Hegelian, and it seems to me that he still retains far too much of the Hegelian formalism in his historical constructions. The well-worked antithesis between object and subject, even after being revised in a positivist sense, is totally inadequate to the burden laid on it by this theory; and if we want really to understand the causes which first hampered, then arrested, and finally paralysed Greek philosophy, we must seek for them in a more concrete order of considerations. Zeller, with perfect justice, attributes the failure of Plato and Aristotle to their defective observation of Nature and their habit of regarding the logical combinations of ideas derived from the common use of words as an adequate representative of the relations obtaining among things in themselves. But it seems an extremely strained and artificial explanation to say that their shortcomings in this respect were due to a confusion of the objective and the subjective, consequent on the imperfect separation of the Greek mind from Nature—a confusion, it is added, which only the advent of a new religion and a new race could overcome.1 It is unfair to make Hellenism as a whole responsible for fallacies which might easily be paralleled in the works of modern metaphysicians; and the unfairness will become still more evident when we remember that, after enjoying the benefit of Christianity and Germanism for a thousand years, the modern world had still to take its first lessons in patience of observation, in accuracy of reasoning, and in sobriety of expression from such men as Thucydides and Hippocrates, Polybius, ArchimÊdes and Hipparchus. Even had the Greeks as a nation been less keen to distinguish between illusion and reality than their successors up to the sixteenth century—a supposition notoriously the reverse of true—it would still have to be explained why Plato and Aristotle, with their prodigious intellects, went much further astray than their predecessors in the study of Nature. And this Zeller’s method does not explain at all.

Again, I think that Zeller quite misconceives the relation between Greek philosophy and Greek life when he attributes the intellectual decline of the post-Aristotelian period, in part at least, to the simultaneous ruin of public spirit and political independence. The degeneracy of poetry and art, of eloquence and history, may perhaps be accounted for in this way, but not the relaxation of philosophical activity. On the contrary, the disappearance of political interests was of all conditions the most favourable to speculation, as witness the Ionians, Democritus, and Aristotle. Had the independence and power of the great city-republics been prolonged much further, it is probable—as the example of the Sophists and Socrates seems to show—that philosophy would have become still more absorbingly moral and practical than it actually became in the Stoic, Epicurean, and Sceptical schools. And theoretical studies did, in fact, receive a great impulse from the Macedonian conquest, a large fund of intellectual energy being diverted from public affairs to the pursuit of knowledge, only it took the direction of positive science rather than of general speculation.2

The cause which first arrested and finally destroyed the free movement of Greek thought was not any intrinsic limitation or corruption of the Greek genius, but the ever-increasing preponderance of two interests, both tending, although in different ways and different degrees, to strengthen the principle of authority and to enfeeble the principle of reason. One was the theological interest, the other was the scholastic interest. The former was the more conspicuous and the more mischievous of the two. From the persecution of Anaxagoras to the prohibition of philosophical teaching by Justinian, we may trace the rise and spread of a reaction towards superstition, sometimes advancing and sometimes receding, but, on the whole, gaining ground from age to age, until from the noontide splendour of Pericles we pass to that long night which stretches in almost impenetrable darkness down to the red and stormy daybreak of the Crusades. And it was a reaction which extended through all classes, including the philosophers themselves. It seems to me that where the Athenian school, from Socrates on, fall short of their predecessors, as in some points they unquestionably do, their inferiority is largely due to this cause. Its influence is very perceptible in weakening the speculative energies of those who stand at the greatest distance from the popular beliefs. It was because dislike for theology occupied so large a place in the thoughts of Epicurus and his disciples, that they valued science only as a refutation of its teaching, instead of regarding it simply as an obstacle to be removed from the path of enquiry. More than this; they became infected with the spirit of that against which they fought, and their absolute indifference to truth was the shadow which it cast on their minds.

The theological interest and the scholastic interest, though not necessarily associated, have, as already observed, a point of contact in their common exaltation of authority. Thus, for our present purpose they may be classified under the more general notion of traditionalism. By this term I understand a disposition to accept as true opinions received either by the mass of mankind or by the best accredited teachers, and to throw these opinions into a form adapted for easy transmission to others. In this sense, traditionalism is Janus-faced, looking on one side to the past and on the other to the future. Now philosophy could only gain general acceptance by becoming a tradition. For a long time the Greek thinkers busied themselves almost exclusively with the discovery of truth, remaining comparatively indifferent to its diffusion. As Plato says, they went their own way without caring whether they took us along with them or not.3 And it was at this period that the most valuable speculative ideas were first originated. At last a strong desire arose among the higher classes to profit by the results of the new learning, and a class of men came into existence whose profession was to gratify this desire. But the Sophists, as they were called, soon found that lessons in the art of life were more highly appreciated and more liberally rewarded than lessons in the constitution of Nature. Accordingly, with the facile ingenuity of Greeks, they set to work proving, first that Nature could not be known, and finally that there was no such thing as Nature at all. The real philosophers were driven to secure their position by a change of front. They became teachers themselves, disguising their lessons, however, under the form of a search after truth undertaken conjointly with their friends, who, of course, were not expected to pay for the privilege of giving their assistance, and giving it for so admirable a purpose. In this co-operative system, the person who led the conversation was particularly careful to show that his conclusions followed directly from the admissions of his interlocutors, being, so to speak, latent in their minds, and only needing a little obstetric assistance on his part to bring them into the light of day. And the better to rivet their attention, he chose for the subject of discussion questions of human interest, or else, when the conversation turned to physical phenomena, he led the way towards a teleological or aesthetical interpretation of their meaning.

Thus, where Zeller says that the Greek philosophers confounded the objective with the subjective because they were still imperfectly separated from Nature, we seem to have come on a less ambitious but more intelligible explanation of the facts, and one capable of being stated with as much generality as his. Not only among the Greeks but everywhere, culture is more or less antagonistic to originality, and the diffusion to the enlargement of knowledge. Thought is like water; when spread over a wider surface it is apt to become stagnant and shallow. When ideas could only live on the condition of being communicated to a large circle of listeners, they were necessarily adapted to the taste and lowered to the comprehension of relatively vulgar minds. And not only so, but the habit of taking their opinions and prejudices as the starting-point of every enquiry frequently led to the investment of those opinions and prejudices with the formal sanction of a philosophical demonstration. It was held that education consisted less in the acquisition of new truth than in the elevation to clearer consciousness of truths which had all along been dimly perceived.

To the criticism and systematisation of common language and common opinion succeeded the more laborious criticism and systematisation of philosophical theories. Such an enormous amount of labour was demanded for the task of working up the materials amassed by Greek thought during the period of its creative originality, and accommodating them to the popular belief, that not much could be done in the way of adding to their extent. Nor was this all. Among the most valuable ideas of the earlier thinkers were those which stood in most striking opposition to the evidence of the senses. As such they were excluded from the system which had for its object the reorganisation of philosophy on the basis of general consent. Thus not only did thought tend to become stationary, but it even abandoned some of the ground which had been formerly won.

Not that the vitality of Hellenic reason gave way simultaneously at every point. The same independent spirit, the same imaginative vigour which had carried physical speculation to such splendid conquests during the first two centuries of its existence were manifested with equal effect when the energies previously devoted to Nature as a whole concentrated themselves on the study of conduct and belief. It was thus that Socrates could claim the whole field of human life for scientific treatment, and create the method by which it has ever since been most successfully studied. It was thus that Plato could analyse and ideally reconstruct all practices, institutions, and beliefs. It was thus that Aristotle, while definitely arresting the progress of research, could still complete the method and create the language through which the results of new research have been established, recognised, and communicated ever since. It was thus that the Stoics advanced from paradox to paradox until they succeeded in co-ordinating morality for all time by reference to the three fundamental ideas of personal conscience, individual obligation, and universal humanity. And not only were dialectics and ethics at first animated by the same enterprising spirit as speculative physics, but their very existence as recognised studies must be ascribed to its decay, to the revolution through which philosophy, from being purely theoretical, became social and didactic. While in some directions thought was made stationary and even retrogressive by the very process of its diffusion, in other directions this diffusion was the cause of its more complete development. Finally, ethics and logic were reduced to a scholastic routine, and progress continued to be made only in the positive sciences, until, here also, it was brought to an end by the triumph of superstition and barbarism combined.

If the cessation of speculative activity among the Greeks needs to be accounted for by something more definite than phrases about the objective and the subjective, so also does its resumption among the nations of modern Europe. This may be explained by two different circumstances—the disappearance of the obstacles which had long opposed themselves to the free exercise of reason, and the stimulus given to enquiry by the Copernican astronomy. After spreading over the whole basin of the Mediterranean, Hellenic culture had next to repair the ravages of the barbarians, and, chiefly under the form of Christianity, to make itself accepted by the new nationalities which had risen on the ruins of the Roman empire. So arduous a task was sufficient to engross, during many centuries, the entire intellectual energies of Western Europe. At last the extreme limits of diffusion were provisionally reached, and thought once more became available for the discovery of new truth. Simultaneously with this consummation, the great supernaturalist reaction, having also reached its extreme limits, had so far subsided, that Nature could once more be studied on scientific principles, with less freedom, indeed, than in old Ionia, but still with tolerable security against the vengeance of interested or fanatical opponents. And at the very same conjuncture it was shown by the accumulated observations of many ages that the conception of the universe on which the accepted philosophy rested must be replaced by one of a directly opposite description. I must confess that in this vast revolution the relation between the objective and the subjective, as reconstituted by Christianity and the Germanic genius, does not seem to me to have played a very prominent part.

If Zeller’s semi-Hegelian theory of history does scant justice to the variety and complexity of causes determining the evolution of philosophy, it also draws away attention from the ultimate elements, the matter, in an Aristotelian sense, of which that evolution consists. By this I mean the development of particular ideas as distinguished from the systems into which they enter as component parts. Often the formation of a system depends on an accidental combination of circumstances, and therefore cannot be brought under any particular law of progress, while the ideas out of which it is constructed exhibit a perfectly regular advance on the form under which they last appeared. Others, again, are characterised by a remarkable fixity which enables them to persist unchanged through the most varied combinations and the most protracted intervals of time. But when each system is regarded as, so to speak, an organic individual, the complete and harmonious expression of some one phase of thought, and the entire series of systems as succeeding one another in strict logical order according to some simple law of evolution, there will be a certain tendency to regard the particular elements of each as determined by the character of the whole to which they belong, rather than by their intrinsic nature and antecedent history. And I think it is owing to this limitation of view that Zeller has not illustrated, so fully as could be desired, the subtler references by which the different schools of philosophy are connected with one another and also with the literature of their own and other times.

An interesting example of the process on which I have just touched is offered by the reappearance and further elaboration of some most important Greek ideas in modern philosophy. In the concluding chapter of this work I have attempted to indicate the chief lines along which such a transmission may be traced. The subject is one which has hitherto been unduly neglected. No critic would be justified in describing the speculative movement of the nineteenth century without constant reference to the metaphysicians and moralists of the two preceding centuries. Yet the dependence of those thinkers on the schools of antiquity is hardly less intimate than our dependence on Spinoza and Hume. Nevertheless, in no work that I am acquainted with has this circumstance been used to elucidate the course pursued by modern thought; indeed, I may say that the persistence of Hellenic ideas down to the most recent times has not been fully recognised by any scholar except Prof. TeichmÜller, who has particularly devoted his attention to the history of conceptions as distinguished from the history of systems.

The introduction of TeichmÜller’s name affords me an opportunity for mentioning that my attention was not directed to his brilliant researches into various questions connected with Greek philosophy, and more particularly with the systems of Plato and Aristotle, until it was too late for me to profit by them in the present work. I allude more particularly to his Studien zur Geschichte der Begriffe (Berlin, 1874), and to his recently published Literarische Fehden im vierten Jahrhundert vor Chr. (Breslau, 1881). The chief points of the former work are, that Plato was really a pantheist or monist, not, as is commonly believed and as I have myself taken for granted, a dualist; that, as a consequence of the suppression of individuality which characterises his system, he did not really accept or teach the doctrine of personal immortality, although he wished that the mass of the people should believe it; that Plato no more attributed a transcendent existence to his ideas than did Aristotle to his substantial forms; and that in putting an opposite interpretation on his old master’s theory, Aristotle is guilty of gross misrepresentation. The most important point of the Literarische Fehden is that Aristotle published his Ethics while Plato was still alive and engaged in the composition of his Laws, and that certain passages in the latter work, of which one relates to free-will and the other to the unity of virtue (861, A ff. and 962 ff.) were intended as a reply to Aristotle’s well-known criticisms on the Platonic theory of ethics.

I have been necessarily brief in my statement of TeichmÜller’s theses; and to judge of them apart from the facts and arguments by which they are supported in the two very interesting volumes above named would be in the highest degree unfair. I feel bound, however, to mention the chief reasons which make me hesitate to accept his conclusions. It seems to me, then, that although Plato was moving in the direction of pantheism—as I have myself pointed out in more than one passage of this work—he never actually reached it. For (i.) he does not, like Plotinus, attempt to deduce his material from his ideal principle, but only blends without reconciling them in the world of sensible experience. (ii.) In opposing the perishable nature of the individual (or rather the particular) to the eternal nature of the universal, he is going on the facts of experience rather than on any necessary opposition between the two, and on experience of material or sensible objects rather than of immaterial souls; while, even as regards material objects, the heavenly bodies, to which he attributes everlasting duration, constitute such a sweeping exception to his rule as entirely to destroy its applicability. (iii.) Plato’s multiplied and elaborate arguments for the immortality of the soul would be superfluous were his only object to prove that the soul, like everything else, contains an eternal element. (iv.) The Pythagorean theory that the soul is a harmony, which Plato rejects, would have been perfectly compatible with the ideal and impersonal immortality which TeichmÜller supposes him to have taught; for while the particular harmony perishes, the general laws of harmony remain. (v.) TeichmÜller does not dispose satisfactorily of Plato’s crowning argument that the idea of life is as inseparable from the soul as heat from fire or cold from snow. He says (op. cit., p. 134) that, on this principle, the individual soul may still perish, just as particular portions of fire are extinguished and particular portions of snow are melted. Yes, but portions of fire do not grow cold, nor portions of snow hot, which and which alone would offer an analogy to the extinction of a soul.

I agree, however, with TeichmÜller that the doctrines of reminiscence and metempsychosis have a purely mythical significance, and I should have expressed my views on the subject with more definiteness and decision had I known that his authority might be quoted in their support. I think that Plato was in a transition state from the Oriental to what afterwards became the Christian theory of retribution. In the one he found an allegorical illustration of his metaphysics, in the other a very serious sanction for his ethics. He felt their incompatibility, but was not prepared to undertake such a complete reconstruction of his system as would have been necessitated by altogether denying the pre-existence of the soul. Of such vacillation Plato’s later Dialogues offer, I think, sufficient evidence. For example, the Matter of the Timacus seems to be a revised version of the Other or principle of division and change, which has already figured as a pure idea, in which capacity it must necessarily be opposed to matter. At the same time, I must observe that, from my point of view, it is enough if Plato inculcated the doctrine of a future life as an important element of his religious system. And that he did so inculcate it TeichmÜller fully admits.4

With regard to the Nicomachean Ethics, I think TeichmÜller has proved this much, that it was written before Aristotle had read the Laws or knew of its existence. But this does not prove that he wrote it during Plato’s lifetime, since the Laws was not published until after Plato’s death, possibly not until several years after. And, published or not, Aristotle may very well have remained ignorant of its existence until his return to Athens, which, according to the tradition, took place about 336 B.C. TeichmÜller does, indeed, suppose that Aristotle spent some time in Athens between his flight from MitylÊnÊ and his engagement as tutor to Alexander (Literarische Fehden, p. 261). But this theory, besides its purely conjectural character, would still allow the possibility of Aristotle’s having remained unacquainted with the Laws up to the age of forty. And it is obvious that the passages which TeichmÜller interprets as replies to Aristotle’s criticisms admit of more than one alternative explanation. They may have originated in doubts and difficulties which spontaneously suggested themselves to Plato in the course of his independent reflections; or, granting that there is a polemic reference, it may have been provoked by some other critic, or by the spoken criticisms of Aristotle himself. For the supposition that Aristotle wrote his Ethics at the early age of thirty-two or thirty-three seems to me so improbable that we should not accept it except under pressure of the strongest evidence. That a work of such matured thought and observation should have been produced by so young a man is, so far as I know, a phenomenon unparalleled in the history of literature. And to this we must add the further circumstance that the Greek mind was not particularly remarkable for precocity in any field except war and statesmanship. We do, indeed, find instances of comparatively juvenile authorship, but none, I believe, of a Greek writer, whether poet, historian, or philosopher, who reached the full maturity of his powers before a considerably advanced period of middle age. That the Ethics is very imperfect I fully admit, and have expressly maintained against its numerous admirers in the course of this work. But, although imperfect, it is not crude. It contains as good a discussion of the subject undertaken as Aristotle was ever capable of giving, and its limitations are not those of an unripe intellect, but of an intellect at all times comparatively unsuited for the treatment of practical problems, and narrowed still further by the requirements of an elaborate speculative system. Now to work out this system must have demanded considerably more labour and independent thought than one can suppose even an Aristotle to have found time for before thirty-three; while the experience of life shown in the Ethics is such as study, so far from supplying, would, on the contrary, have delayed. Moreover, the Rhetoric, which was confessedly written before the Ethics, exhibits the same qualities in about an equal degree, and therefore, on TeichmÜller’s theory, testifies to a still more extraordinary precocity. And there is the further circumstance that while Aristotle is known to have begun his public career as a teacher of rhetoric, his earliest productions seem to have been of a rather diffuse and declamatory character, quite opposed to the severe concision which marks the style both of the Rhetoric and of the Ethics. In addition to these general considerations, one may mention that in a well-known passage of the Ethics, referring to a question of logical method (I., iv.), Plato is spoken of in the imperfect tense, which would seem to imply that he was no longer living when it was written. Speaking from memory, I should even be inclined to doubt whether the mention of a living writer by name at all is consistent with Aristotle’s standard of literary etiquette.

These are difficulties which TeichmÜller has, no doubt, fully weighed and put aside as not sufficiently strong to invalidate his conclusions. I have stated them in order to show that enough can be said for the old view to justify the republication of what was written on the assumption of its unquestionable truth. Moreover, researches conducted with so much skill and learning as those of TeichmÜller demand some public acknowledgment in a work like the present, even when the results are such that the writer cannot see his way to accepting them as satisfactorily made out. There are many English scholars more competent than I am to discuss the whole question at issue. Perhaps these lines may induce some of them to give it the attention which it merits, but which, in England at least, it does not seem to have as yet received.

My obligations to other writers have been acknowledged throughout this work, so far as I was conscious of them, and so far as they could be defined by reference to specific points. I take the present opportunity for mentioning in a more general way the valuable assistance which I have derived from Schwegler’s Geschichte der Griechischen Philosophie, Lange’s Geschichte des Materialismus, and DÜhring’s Geschichte der Philosophie. The parallel between Socrates, Giordano Bruno, and Spinoza was probably suggested to me by DÜhring, as also were some points in my characterisation of Aristotle. As my view of the position occupied by Lucretius with respect to religion and philosophy differs in many important points from that of Prof. Sellar, it is the more incumbent on me to state that, but for a perusal of Prof. Sellar’s eloquent and sympathetic chapters on the great Epicurean poet, my own estimate of his genius would certainly not have been written in its present form and would probably not have been written at all.

On the whole, I am afraid that my acquaintance with the modern literature of the subject will be found rather limited for an undertaking like the present. But I do not think that wider reading in that direction would have much furthered the object I had in view. That object has been to exhibit the principal ideas of Greek philosophy in the closest possible connexion with the characters of their authors, with each other, with their developments in modern speculation, with the parallel tendencies of literature and art, with the history of religion, of physical science, and of civilisation as a whole. To interpret all things by a system of universal references is the method of philosophy; when applied to a series of events this method is the philosophy of history; when the events are ideas, it is the philosophy of philosophy itself.