Zeno, of Cittium, a city of Cyprus, an elder contemporary of Antigonus Gonatas, king of Macedon, is generally given as the founder of the Stoical school. Deprived of his property by shipwreck, he took refuge in philosophy, incited also by an inner bias to such pursuits. He at first became a disciple of the Cynic Crateas, then of Stilpo, one of the Megarians, and lastly he betook himself to the Academy, where he heard the lessons of Xenocrates and Polemo. Hence the eclectic character of his teaching. It has in fact been charged against him, that differing but little if at all from the earlier schools, he attempted to form a school of his own, with a system wherein he had changed nothing but names. He opened a school at Athens, in the “variegated porch,” so called from the paintings of Polygnotus, with which it was adorned, whence his adherents received the name of “philosophers of the porch” (Stoics). Zeno is said to have presided over his school for fifty-eight years, and at a very advanced age to have put an end to his existence. He is praised for the temperance and the austerity of his habits, while his abstemiousness is proverbial. The monument in his honor, erected after his death by the Athenians, at the instance of Antigonus, bore the high but simple eulogium that his life had been in unison with his philosophy. Cleanthes was the successor of Zeno in the Stoic school, and faithfully carried out the method of his master. Cleanthes was succeeded by Chrysippus, who died about 208 B. C. He has been regarded as the chief prop of this school, in which respect it was said of him, that without a Chrysippus there would never have been a Porch. At all events, as Chrysippus was an object of the greatest veneration, and of almost undisputed authority with the later Stoics, he ought to be considered as the principal founder of the school. He was a writer so voluminous, that his works have been said to amount to seven hundred and five, among which, however, were repeated treatises upon the same propositions, and citations without measure from poets and historians, given to prove and illustrate his opinions. Not one of all his writings has come down to us. Chrysippus closes the series of the philosophers who founded the Porch. The later heads of the school, as PanÆtius, the friend of the younger Scipio (his famous work De Officiis, Cicero has elaborated in his treatise of the same name), and Posidonius, may be classed with Cicero, Pompeius, and others, and were eclectic in their teachings. The Stoics have connected philosophy most intimately with the duties of practical life. Philosophy is with them the practice of wisdom, the exercise of virtue. Virtue and science are with them one, in so far at least that they divide virtue in reference to philosophy into physical, ethical, and logical. But though they go on according to this threefold division, and treat of logic and physics, and though they even rank physics higher than either of the other sciences, regarding it as the mother of the ethical and the science of the Divine, yet do we find their characteristic standpoint most prominently in their theory of morals.

1. Logic.—We have already said that it is the breach between subject and object, which forms the basis of all post-Aristotelian philosophy. The beginning of this philosophy of subjectivity is found with the Stoics. The feature most worthy of notice in their logic, is the striving after a subjective criterion of the truth, by which they might distinguish the true representation from the false. Since they limited all scientific knowledge to the knowledge of the senses, they found this criterion in that which was evident in the sensuous impression. They conceived that they had answered the whole problem, in affirming that the true or conceivable representation reveals not only itself, but also its object: it, they said, is nothing else than a representation which is produced by a present object in a manner like itself.

2. Physics.—In their physics, where they follow for the most part Heraclitus, the Stoics are distinguished from their predecessors, especially from Plato and Aristotle, by their thoroughly carried out proposition that nothing uncorporeal exists, that every thing essential is corporeal (just as in their logic they had sought to derive all knowledge from the sensuous perception). This sensualism or materialism of the Stoics which, as we have seen in their logic, lies at the basis of their theory of knowledge, might seem foreign to all their moral and idealistic tendencies, but is clearly explained from their subjective standpoint, for, when the thought has become so intensely engrossed in the subject, the objective world can only be regarded as a corporeal and material existence. The most immediate consequence of such a view is their pantheism. Aristotle before them had separated the Divine Being from the world, as the pure and eternal form from the eternal matter; but so far as this separation implied a distinction which was not simply logical, but actual and real, the Stoics would not admit it. It seemed to them impossible to dissever God from matter, and they therefore considered God and the world as power and its manifestation, and thus as one. Matter is the passive ground of things, the original substratum for the divine activity: God is the active and formative energy of matter dwelling within it, and essentially united to it: the world is the body of God, and God is the soul of the world. The Stoics, therefore, considered God and matter as one identical substance, which, on the side of its passive and changeable capacity they call matter, and on the side of its active and changeless energy, God. But since they, as already remarked, considered the world as ensouled by God in the light of a living and rational being, they were obliged to treat the conception of God not only in a physical but also in its ethical aspect. God is not only in the world as the ruling and living energy of this great ???? (animal), but he is also the universal reason which rules the whole world and penetrates all matter; he is the gracious Providence which cares for the individual and the whole; he is wise, and is the ground of that natural law which commands the good and forbids the evil; he punishes and rewards; he possesses a perfect and blessed life. But accustomed to regard every thing spiritual only in a sensuous way, the Stoics were obliged to clothe this ideal conception of God in a material form, apprehending it as the vital warmth or an original fire, analogous to the view of the earlier natural philosophers, who held that the soul, and even reason itself, consisted in the vital warmth. The Stoics express this thought in different ways. At one time they call God the rational breath which passes through all nature; at another, the artistic fire which fashions or begets the universe; and still again the ether; which, however, they hardly distinguish from the artistic fire. From these varying views, we see that it did not belong to the Stoics to represent the conception of God in any determinate kind of existence. They availed themselves of these expressions only to indicate that God, as the universal animating energy in the world, could not be disconnected from a corporeal agency. This identification of God and the world, according to which the Stoics regarded the whole formation of the universe as but a period in the development of God, renders their remaining doctrine concerning the world very simple. Every thing in the world seemed to them to be permeated by the divine life, and was regarded as but the flowing out of this most perfect life through certain channels, until it returned in a necessary circle back again to itself. It is not necessary here to speak more closely of the physics of this school.

3. The Ethics.—The ethics of the Stoics is most closely connected with their physics. In the physics we saw the rational order of the universe as it existed through the divine thought. In the ethics, the highest law of human action, and thus the whole moral legality of life is dependent upon this rational order and conformity to law in universal nature, and the highest good or the highest end of our strivings is to shape our life according to this universal law, to live in conformity with the harmony of the world or with nature. “Follow nature,” or “live in harmony with nature,” is the moral maxim of the Stoics. More accurately: live in harmony with thy rational nature so far as this has not been distorted nor refined by art, but is held in its natural simplicity.

From this moral principle, in which we have also the Stoic conception of virtue, the peculiarities of their theory of morals follow with logical necessity.

(1.) Respecting the Relation of Virtue to Pleasure.—When the demand is made that the life should be in conformity with nature, the individual becomes wholly subjected to the universal, and every personal end is excluded. Hence pleasure, which of all ends is the most individual, must be disregarded. In pleasure that activity in which blessedness consists is abated, and this could only appear to the Stoics as a restraint of life, and thus as an evil. Pleasure is not in conformity with nature, and is no end of nature, says Cleanthes; and though other Stoics relax a little from the strictness of this opinion, and admit that pleasure may be according to nature, and is to be considered in a certain degree as a good, yet they all held fast to the doctrine, that it has no moral worth and is no end of nature, but is only something which is accidentally connected with the free and fitting activity of nature, while itself is not an activity, but a passive condition of the soul. In this lies the whole severity of the Stoic doctrine of morals; every thing personal is cast aside, every external end of action is foreign to the moral man, the action in wisdom is the only good. From this follows directly:

(2.) The View of the Stoics Concerning External Good.—If virtue, as the activity in conformity to nature, is exclusively a good, and if it alone can lead to happiness, then external good of every kind is something morally indifferent, and can neither be the object of our striving nor the end of any moral action. The action itself and not that towards which it tends is good. Hence such special ends as health, wealth, &c., are in themselves worthless and indifferent. They may result either in good or evil, and when deprived of them the happiness of the virtuous man is not destroyed. The Stoics yield from the rigor of their fundamental principle only in a single instance. They admit that there may be a distinction among indifferent things; that while none of these can be called a moral good, yet some may be preferable to others, and that the preferable, so far as it contributes to a life in conformity to nature, should enter into the account of a moral life. So the sage will prefer health and wealth when these are balanced in the choice with sickness and poverty, but though these objects have been rationally chosen, he does not esteem them as really good, for they are not the highest, they are inferior to the virtuous acting, in comparison with which every thing else sinks to insignificance. In making this distinction between the good and the preferable, we see how the Stoics exclude from the good every thing relative, and hold fast to it alone in its highest significance.

(3.) This abstract apprehension of the conception of virtue is still farther verified in the rigid antagonism which the Stoics affirmed between virtue and not-virtue, reason and sense. Either, they conclude, reason is awakened in the life of man and holds the mastery over him, or it is not awakened, and he serves his irrational instincts. In the former case we have a good and in the latter a bad man, while between these two cases as between virtue and vice, there is no mean. And since virtue cannot be partially possessed, but the man must be wholly virtuous or not at all, it follows that virtue as such is without degree, just as truth is, and hence also all good acts are equally good, because they spring from the full freedom of the reason, and all vicious ones equally bad, because they are impelled by the irrational instinct.

(4.) But this abstractedness of the moral standpoint, this rigid opposition of reason and irrationality, of the highest good and the individual good, of virtue and pleasure, has no power to furnish a system of concrete moral duties. The universal moral principle of the Stoics fails in its applicability to the individual instance. The Stoic morals has no concrete principle of moral self-determination. How must we act in every individual instance, in every moral relation, so as to act according to nature? To this inquiry Stoicism can give no answer. Its system of particular duties is thus wholly without a scientific form, and is only held together by some universal conceptions which it contains. For the most part they satisfy themselves with describing in general terms the action according to nature, and with portraying their ideal of the wise man. The characteristics which they give this ideal are partly paradoxical. The wise man is free even in chains, for he acts from himself unmoved by fear or desire; the wise man alone is king, for he alone is not bound by laws and owes fealty to no one; he is the true rich man, the true priest, prophet, and poet. He is exalted above all law and every custom; even that which is most despicable and base—deception, suicide, murder—he may commit at a proper time and in a virtuous character. In a word the Stoics describe their wise man as a god, and yield it to him to be proud and to boast of his life like Zeus. But where shall we find such a sage? Certainly not among the living. In the time long ago there may have been a perfect sage of such a pattern; but now, and for a long time back, are men at best only fools who strive after wisdom and virtue. The conception of the wise man represented, therefore, to the Stoics only an ideal, the actualization of which we should strive after, though without ever hoping to reach it; and yet their system of particular duties is almost wholly occupied in portraying this unreal and abstract ideal—a contradiction in which it is seen most clearly that their whole standpoint is one of abstract subjectivity.