As regards the Physics of the Stoics, we may in the first place say that it does not contain much that is peculiar to itself, since it is rather a compendium of the Physics of older times, and more especially of that of Heraclitus. However, each of the three schools now being dealt with has had a very characteristic and definite terminology, which is more than can be altogether said of the philosophy of Plato and Aristotle. Thus we must now make ourselves familiar with the particular expressions used and with their significance. The following is the essence of the Physics of the Stoics: The determining reason (λόγος) is the ruling, all-productive substance and activity, extended throughout all, and constituting the basis of all natural forms; this preponderating substance, in its rational effectuating activity, they call God. It is a world-soul endowed with intelligence, and, since they called it God, this is really Pantheism. But all Philosophy is pantheistic, for it goes to prove that the rational Notion is in the world. The hymn of Cleanthes is to this effect: “Nothing happens on earth without thee, O Dæmon, neither in the ethereal pole of the heavens, nor in the sea, excepting what the wicked do through their own foolishness. But thou knowest how to make crooked things straight, and thou orderest that which is without order, and the inimical is friendly to thee. For thus hast thou united everything into one, the good to the evil; thus one Notion (λόγος) is in everything that ever was, from which those mortals who are evil flee. How unhappy are they, too, who, ever longing to possess the good, do not perceive God’s universal law, nor listen thereto, the which if they but obeyed with reason, (σὺν νῷ) they would attain a good and happy life!”[127] The Stoics thus believed the study of nature to be essential, in order to know in nature its universal laws, which constitute the universal reason, in order that we might also know therefrom our duties, the law for man, and live conformably to the universal laws of nature. “Zeno,” according to Cicero (De nat. Deor. I. 14), “holds this natural law to be divine, and believes that it has the power to dictate the right and prohibit what is wrong.” Thus the Stoics desired to know this rational Notion which rules in nature not altogether on its own account; and the study of nature was consequently to them rather a mere matter of utility.
If we are now to give some further idea of what these Physics are, we may say that the Stoics distinguish in the corporeal—although nature is only the manifestation of one common law—the moment of activity and that of passivity; the former is, according to Aristotle, active reason, or, according to Spinoza, natura naturans; the latter passive reason, or natura naturata. The latter is matter, substance without quality, for quality is, generally speaking, form, i.e. that which forms universal matter into something particular. This is indeed the reason likewise that with the Greeks quality is called τὸ ποιόν, just as we in German derive Beschaffenheit from Schaffen—that which is posited, the negative moment. But the actuating, as the totality of forms, is, according to the Stoics, the Notion in matter; and this is God. (Diog. Laërt. VII. 134.)
As regards the further nature of these forms, these universal laws of nature, and the formation of the world, the Stoics have in the main adopted the ideas of Heraclitus, for Zeno studied him very particularly (supra, p. 239). They thus make fire the real Notion, the active principle which passes into the other elements as its forms. The world arises by the self-existent gods driving the universal material substance (οὐσίαν) out of the fire, through the air, into the water; and as in all generation the moisture which surrounds a seed comes first as the begetter of all that is particular, so that conception, which in this respect is called seed-containing (σπερματικός), remains in the water and then actuates the indeterminate Being of matter into the origination of the other determinations. The elements, fire, water, air and earth, are consequently primary. Respecting them the Stoics speak in a manner which has no longer any philosophic interest. “The coagulation of the denser parts of the world forms the earth; the thinner portion becomes air, and if this becomes more and more rarefied, it produces fire. From the combination of these elements are produced plants, animals, and other kinds of things.” The thinking soul is, according to them, of a similar fiery nature, and all human souls, the animal principle of life, and also plants, are parts of the universal world-soul, of the universal fire; and this central point is that which rules and impels. Or, as it is put, souls are a fiery breath. Sight, in the same way, is a breath of the ruling body (ἡγεμονικοῦ) transmitted to the eyes; similarly hearing is an extended, penetrating breath, sent from the ruling body to the ears.[128]
Respecting the process of nature we may further say this: Fire, Stobæus tells us (Eclog. phys. I. p. 312), is called by the Stoics an element in a pre-eminent sense, because from it, as the primary element, all else arises through a transformation, and in it, as in an ultimate, everything is fused and becomes dissolved. Thus Heraclitus and Stoicism rightly comprehended this process as a universal and eternal one. This has even been done by Cicero, though in a more superficial way; in this reflection he falsely sees the conflagration of the world in time and the end of the world, which is quite another matter. For in his work De natura Deorum (II. 46) he makes a Stoic speak thus: “In the end (ad extremum) everything will be consumed by fire; for if all moisture becomes exhausted the earth can neither be nourished, nor can air return into existence. Thus nothing but fire remains, through whose reanimation and through God the world will be renewed and the same order will return.” This is spoken after the manner of the ordinary conception. But to the Stoics everything is merely a Becoming. However deficient this may be, God, as the fiery principle, is yet to them the whole activity of nature, and likewise the rational order of the same, and in this lies the perfect pantheism of the Stoic conception of nature. Not only do they call this ordering force God, but also nature, fate or necessity (εἱμαρμένην), likewise Jupiter, the moving force of matter, reason (νοῦν) and foresight (πρόνοιαν); to them all these are synonymous.[129] Because the rational brings forth all, the Stoics compare this impelling activity to a seed, and say: “The seed which sends forth something rational (λογικόν) is itself rational. The world sends forth the seeds of the rational and is thus in itself rational;” that is to say, rational both generally, in the whole, and in each particular existent form. “All beginning of movement in any nature and soul rises from a ruling principle, and all powers which are sent forth upon the individual parts of the whole proceed from the ruling power as from a source; so that each force that is in the part is also in the whole, because the force is distributed by the ruling power in it. The world embraces the seed-containing conceptions of the life which is in conformity with the conception,” i.e. all particular principles.[130] The Physics of the Stoics is thus Heraclitean, though the logical element is entirely at one with Aristotle; and we may regard it as being such. However, speaking generally, only those belonging to earlier times had a physical element in their philosophy: those coming later neglected Physics entirely and kept alone to Logic and to Ethics.
The Stoics again speak of God and the gods according to the popular manner of regarding them. They say that “God is the ungenerated and imperishable maker of all this disposition of things, who after certain periods of time absorbs all substance in Himself, and then reproduces it from Himself.”[131] There no definite perception is reached, and even the above relation of God, as absolute form, to matter has attained no developed clearness. The universe is at one time the unity of form and matter, and God is the soul of the world; at another time, the universe, as nature, is the Being of the constituted matter, and that soul is antagonistic to it, but the activity of God is a disposition of the original forms of matter.[132] This opposition is devoid of the essentials of union and division.
Thus the Stoics remain at the general conception that each individual is comprehended in a Notion, and this again in the universal Notion, which is the world itself. But because the Stoics recognized the rational as the active principle in nature, they took its phenomena in their individuality as manifestations of the divine; and their pantheism has thereby associated itself with the common ideas about the gods as with the superstitions which are connected therewith (p. 235), with belief in all sorts of miracles and with divination—that is to say, they believe that in nature there are intimations given which men must receive through divine rites and worship. Epicureanism, on the contrary, proceeds towards the liberation of men from this superstition to which the Stoics are entirely given over. Thus Cicero, in his work De divinatione, has taken the most part of his material from them, and much is expressly given as being the reasoning of the Stoics. When, for example, he speaks of the premonitory signs given in connection with human events, all this is conformable with the Stoic philosophy. The fact that an eagle flies to the right, the Stoics accepted as a revelation of God, believing that thereby it was intimated to men what it was advisable for them to do in some particular circumstances. Just as we find the Stoics speaking of God as having universal necessity, to them God, as Notion, has hence a relation to men and human ends likewise, and in this respect He is providence; thus they now arrived at the conception of particular gods also. Cicero says in the work quoted above (II. 49): “Chrysippus, Diogenes and Antipater argued thus: If gods exist, and if they do not let men know beforehand what is to happen in the future, they cannot love men, or else they themselves do not know what stands before them in the future, or they are of opinion that it does not signify whether man knows it or not, or they consider such a revelation beneath the dignity of their majesty, or they cannot make it comprehensible to men.” All this they refute, for amongst other things they say that nothing can exceed the beneficence of the gods, &c. Thus they draw the conclusion that “the gods make known to men the future”—a system of reasoning in which the entirely particular ends of individuals also form the interests of the gods. To make men know and comprehend at one time and not at another, is an inconsistency, i.e. an incomprehensibility, but this very incomprehensibility, this obscurity, is the triumph of the common way of regarding religions affairs. Thus in the Stoics all the superstitions of Rome had their strongest supporters; all external, teleological superstition is taken under their protection and justified. Because the Stoics started from the assertion that reason is God (it certainly is divine, but it does not exhaust divinity), they immediately made a bound from this universal to the revelation of that which operates for the sake of individual ends. The truly rational is doubtless revealed to men as the law of God; but the useful, what is in conformity with individual ends, is not revealed in this truly divine revelation.
[2. Logic.]
In the second place, as to the intellectual side of the philosophy, we must first of all. consider the principle of the Stoics in answering the question of what the true and rational is. In regard to the source of our knowledge of truth, or of the criterion, which in those times used to be discussed (Vol. I. p. 474, Vol. II. p. 233), the Stoics decided that the scientific principle is the conception that is laid hold of (φαντασία καταληπτική), for the true as well as for the good; for the true and good are set forth as content or as the existent. Thus a unity of apprehending thought and Being is set forth in which neither can exist without the other; by this is meant not sensuous conception as such, but that which has returned into thought and become proper to consciousness. Some of the older Stoics, amongst whom we certainly find Zeno, called this criterion the very truth of reason (ὀρθὸς λόγος). Ordinary conception on its own account (φαντασία) is an impression (τύπωσις), and for it Chrysippus used the expression alteration (ἐτεροίωσις).[133] But that the conception should be true, it must be comprehended; it begins with feeling, whereby in fact the type of another is brought into us; the second step is that we should transform this into part of ourselves, and this first of all occurs through thought.
According to Cicero’s account (Academ. Quæst. IV. 47), Zeno illustrated the moments of this appropriation by a movement of the hand. When he showed the open palm he said that this was a sensuous perception; when he bent the fingers somewhat, this was a mental assent through which the conception is declared to be mine; when he pressed them quite together and formed a fist, this was comprehension (κατάληψις), just as in German we speak of comprehension [Begreifen] when by means of our senses we lay hold of anything in a similar way; when he then brought the left hand into play and pressed together that fist firmly and forcibly, he said that this was science, in which no one but the wise man participated. This double pressure, my pressing with the other hand that which is grasped, is said to signify conviction, my being conscious of the identity of thought with the content. “But who this wise man is or has been the Stoics never say,” adds Cicero; and of this we shall afterwards have to speak in greater detail. In fact, the matter is not made clear through this gesticulation of Zeno’s. The first action, the open hand, is sensuous apprehension, immediate seeing, hearing, &c.; the first motion of the hand is then, speaking generally, spontaneity in grasping. This first assent is likewise given by fools; it is weak, and may be false. The next moment is the closing of the hand, comprehension, taking something in; this makes the ordinary conception truth, because the ordinary conception becomes identical with thought. By this my identity with this determination is indeed set forth, but this is not yet scientific knowledge, for science is a firm, secure, unchangeable comprehension through reason or thought, which is that which rules or directs the soul. Midway between scientific knowledge and folly is the true Notion as the criterion, although as yet it is not itself science; in it thought gives its approbation to existence and recognizes itself, for approbation is the harmony of a thing with itself. But in scientific knowledge a perception of the first elements and determinate knowledge through thought of the object is contained. Thus the ordinary conception as apprehended is thought; scientific knowledge is the consciousness of thought, the knowledge of that harmony.
We may also give our assent to these conclusions of the Stoics with their various stages, since in them there is a perception which is undoubtedly true. In this we have an expression of the celebrated definition of the truth, by which it is made the harmony of object and consciousness; but at the same time it is well to remark that this is to be understood simply, and not as indicating that consciousness had a conception, and that on the other side stood an object, which two had to harmonize with one another, and hence that a third was necessarily brought into existence which had to compare them. Now this would be consciousness itself, but what this last can compare is nothing more than its conception, and—not the object, but—its conception again. Consciousness thus really accepts the conception of the object; it is by this approbation that the conception actually receives truth—the testimony of mind to the objective rationality of the world. It is not, as is ordinarily represented, that a round object here impresses itself upon wax, that a third compares the form of the round and of the wax and, finding them to be similar, judges that the impress must have been correct, and the conception and the thing have harmonized. For the action of thought consists in this, that thought in and for itself gives its approbation and recognizes the object as being in conformity with itself; this it is in which lies the power of truth—or approbation is the expression of this harmony, or judgment itself. In this, say the Stoics, the truth is contained; it is an object which is likewise thought, so that the thought that gives its assent is the ruling thought which posits the harmony of subject with content. The fact that anything is or has truth is thus not because it is (for this moment of Being is only ordinary conception), but the fact that it is, has its power in the approbation of consciousness. But this thought alone and for itself is not the truth, nor is the truth as such contained in it, for the Notion requires the objective element and is only the rational consciousness respecting the truth. But the truth of the object itself is contained in the fact that this objective corresponds to thought, and not the thought to the objective; for this last may be sensuous, changeable, false, and contingent, and thus it is untrue for mind. This is the main point as far as the Stoics are concerned, and even if we discover the Stoic speculative doctrines from their antagonists better than from their originators and advocates, yet from them, too, this idea of unity proceeds; and while both sides of this unity are opposed, both are necessary, but thought is essential reality. Sextus Empiricus (adv. Math. VIII. 10) understands this thus: “The Stoics say that as regards the perceptible and that which is thought some things alone are true; what is felt, however, is not immediate (έξ εὐθείας), for it becomes true for the first time through its relation to the thought that corresponds to it.” Thus neither is immediate thought the true, excepting in so far us it corresponds to the Notion and is known through the working out of rational thought.