singly, and any one sensation is liable to be confirmed or weakened by the connected sensations. We may believe, for instance, that we see the figure of Socrates; and this belief will be confirmed if we think we recognize his voice. If then all the associated sensations agree in confirming our belief, such a belief is called parтaoía άπeρíσжαστos, an undisturbed presentation. The highest degree of probability is when we have further investigated the conditions under which the sensation occurred (such as the soundness of the organ, the distance from the object etc.), and find nothing to raise suspicion as to its reality; belief is then called φαντασία περιωδευμένη, 2 thoroughly explored presentation. We have very little information as to the particular doctrines to which Carneades assigned probability. One tradition says that in his old age, he relaxed in his irony, and became more free-spoken', but his successor Clitomachus professed that he had never been able to ascertain what his real belief was2.

The Reformed Academy may be regarded as commencing with Philo of Larissa, a pupil of Clitomachus and one of Cicero's teachers. In it we see a return to dogmatism combined with an eclectic tendency which showed itself most strongly in Philo's pupil Antiochus, who endeavoured to strengthen the Academy by uniting Stoic and Peripatetic doctrines with the original Platonism. Further details will be given when we come to speak of the influence of the Roman spirit on the development of philosophy.

We turn now to the two most important developments of post-Aristotelian philosophy, Stoicism and Epicureanism. To understand them it is necessary to look for a 1 See Zeller III. I. p. 5313. 2 Cic. Acad. 11. 139.

moment at the changes which had been brought about by the conquests of Alexander. While Greece proper lost its national life, the Greek language and Greek civilization spread throughout the world, and the Greeks in their turn became familiarized with Oriental thought and religion. Thus the two main supports of the authoritative tradition by which practical life had hitherto been regulated, the law of the State and the old religion of Greece, were shaken from their foundations. The need which was most strongly felt by the best minds was to find some substitute for these, some principle of conduct which should enable a man to retain his self-respect under the rule of brute force to which all were subject. It must be something which would enable him to stand alone, to defy the oppressor, to rise superior to circumstances. Such a principle the Stoics boasted to have found1. Zeno, the founder of the school, was a native of Citium in Cyprus. He came to Athens about 320 B.C. and attended the lectures of Crates the Cynic and afterwards of Stilpo the Megarian and of some of the Academics, and began to teach in the σroά Tolkiλŋ about 308 B.C. He was succeeded by Cleanthes of Assos in Asia Minor about 260 B.C. Among his other pupils were Aristo of Chius, Herillus of Carthage, Persaeus, who like his master was a native of Citium, and Aratus of Soli in Cilicia, the author of two astronomical poems translated by Cicero (N. D. II. 104-115). Cleanthes was succeeded by Chrysippus of Soli (b. 280, d. 206), who did so much to develop and systematize the Stoic philosophy that he was called the Second Founder of the

1 See the interesting treatise on Stoicism by W. W. Capes in the S. P. C. K. series, and Essay VI of the Introduction to Grant's Ethics.

school'. Next came Zeno of Tarsus and Diogenes of Babylon, one of the three ambassadors to Rome in 155 B.C. From this time forward Stoicism begins to show a softened and eclectic tendency, as we may see in Panaetius of Rhodes (180-III B.C.), and also in his pupil Posidonius of Apamea in Syria, of whom we shall have more to say hereafter.

The end of philosophy with the Stoics was purely practical. Philosophy is identical with virtue. But since virtue consists in bringing the actions into harmony with the general order of the world, it is essential to know what this order is, and thus we arrive at the famous triple division of philosophy into physics, including cosmology and theology, which explains the nature and laws of the universe; logic, which ensures us against deception and supplies the method for attaining to true knowledge; ethics, which draws the conclusion for practical life. The Stoics were famed for their logical subtilties, and are often referred to under the name Dialectici. They included in Logic both Rhetoric and Grammar, and made great improvements in the theory of the latter subject. The chief point of interest however in their Logic is their theory as to the criterion. They considered the soul to resemble a sheet of blank paper on which impressions (pavraoíai) were made through the senses.

1 Cf. the line εἰ μὴ γὰρ ἦν Χρύσιππος οὐκ ἂν ἦν στοά.

2 Plut. Plac. Phil. IV. II.

3 Cleanthes held that each impression was literally a material impression on the soul, like that of a signet-ring on wax: Chrysippus thought this inconsistent with the infinite variety of impressions which we are continually receiving, and preferred to speak of them as modifications (èrepoureus) of the soul. See Sext. Math. VII. 228.

The concept (vvoia) was produced from the impressions by generalization, which might be either spontaneous and unconscious, giving rise to common ideas or natural anticipations (κοιναὶ ἔννοιαι, ἔμφυτοι προλήψεις), or it might be conscious and methodical, giving rise to artificial concepts. In entire opposition to Plato they held that the individual object alone had real existence; the universal, the general term, existed only in the mind as subjective thought. The truth or falsehood of these impressions and conceptions depended on their possession οἱ τὸ καταληπτικόν, the power of carrying conviction. An impression which was not merely assented to, but forced itself irresistibly on the mind, was a καταληπτικὴ φαντασία a perception that has a firm grasp of reality'. The same irresistible evidence attaches to a πρóλŋɩs2, but artificial concepts required to have their truth proved by being connected with one or other of these criteria. The ten Categories of Aristotle were reduced by the Stoics to four, (1) the substratum, Tò vлoкeíμevov, (2) the essential quality, To Tolov, (3) the condition, Tò us exov, (4) the relation, τὸ πρός τι πὼς ἔχον.

The physical theory of the Stoics is a pantheistic materialism. The only real existences are such as can act and be acted upon, and these are bodies, for like can'

1 Zeno compared the simple impression or sensation (pavraola) to the touching of an object with the outstretched fingers; the mental assent which follows (avyкatáleσis) to a half closure of the hand upon the object; the distinct apprehension (karádnyis) to a tight grasp; knowledge itself to the grasping of the fist by the other hand, so as to keep it more firmly closed.

2 Cicero's renderings of the above technical terms are as follows: φαντασία visum, κοιναὶ ἔννοιαι communes notiones, ἔμφυτοι προλήψεις insitae anticipationes, κατάληψις comprehensio, συγκατάθεσις assensio.

only act on like'. But these bodies are not moved simply by mechanical laws, as Democritus supposed. The whole universe is an embodied spiritual force, of which we may call one part passive, one part active, but all is alike material. The active portion is soul, a fiery ether pervading the whole, but having its principal seat in the heaven which encompasses it on every side; the passive portion consists mainly of the inferior elements, water and earth. These latter proceed from the former and are periodically reabsorbed into it in the world-conflagration. The universe itself, as a perfect living creature, is rightly called God, but the name is more particularly given to the soul of the universe, who is also known by many descriptive appellations, Rational or Artistic Fire (Tuρ voeρóν, Tûρ Texvikóv), All-penetrating Air, Spirit, Reason, Nature, Providence, Destiny, Law, Necessity, the Ruling Principle (To nyeμovikóv), and, with reference to his creative and 'informing' power, the Generative Reason (Móyos σTeρμаTIKÓS). The gods of the popular religion represented different activities of the one true Deity. Thus Zeus, one God under many names as Cleanthes calls him, is denominated Hera, when we think of him as pervading the air, Poseidon as pervading water, Demeter as pervading earth: again Demeter is the name we give to Zeus when we think of him as the giver of corn, Dionysus, when we think of him as the giver of wine.

1 Not only substances, but feelings and attributes were regarded as corporeal. Thus the virtues, and even the seasons of the year, were called animals or bodies. These paradoxical modes of speech were explained by saying, that virtue denoted a certain tension or elasticity (Tóvos) of the psychical element, ether; that when we speak of summer, we mean air of a certain temperature, &c.