Vitae philosophorum

Andron of Argos is reported by Aristotle[*](Fr. 103 Rose.) to have travelled across the waterless deserts of Libya without drinking. Moreover, one man fancies the profession of medicine, another

The third mode depends on the differences between the sense-channels in different cases, for an apple gives the impression of being pale yellow in colour to the sight, sweet in taste and fragrant in smell. An object of the same shape is made to appear different by differences in the mirrors reflecting it. Thus it follows that what appears is no more such and such a thing than something different.

The fourth mode is that due to differences of condition and to changes in general; for instance, health, illness, sleep, waking, joy, sorrow, youth, old age, courage, fear, want, fullness, hate, love, heat, cold, to say nothing of breathing freely and having the passages obstructed. The impressions received thus appear to vary according to the nature of the conditions. Nay, even the state of madmen is not contrary to nature; for why should their state be so more than ours? Even to our view the sun has the appearance of standing still. And Theon of Tithorea used to go to bed and walk in his sleep, while Pericles’ slave did the same on the housetop.

The fifth mode is derived from customs, laws, belief in myths, compacts between nations and dogmatic assumptions. This class includes considerations with regard to things beautiful and ugly, true and false, good and bad, with regard to the gods, and with regard to the coming into being and the passing away of the world of phenomena. Obviously the same thing is regarded by some as just and by others as unjust, or as good by some and

Different people believe in different gods; some in providence, others not. In burying their dead, the Egyptians embalm them; the Romans burn them; the Paeonians throw them into lakes. As to what is true, then, let suspension of judgement be our practice.

The sixth mode relates to mixtures and participations, by virtue of which nothing appears pure in and by itself, but only in combination with air, light, moisture, solidity, heat, cold, movement, exhalations and other forces. For purple shows different tints in sunlight, moonlight, and lamplight; and our own complexion does not appear the same at noon and when the sun is low.

Again, a rock which in air takes two men to lift is easily moved about in water, either because, being in reality heavy, it is lifted by the water or because, being light, it is made heavy by the air. Of its own inherent property we know nothing, any more than of the constituent oils in an ointment.

The seventh mode has reference to distances, positions, places and the occupants of the places. In this mode things which are thought to be large appear small, square things round; flat things appear to have projections, straight things to be bent, and colourless coloured. So the sun, on account of its distance, appears small, mountains when far away appear misty and smooth, but when near at hand

Furthermore, the sun at its rising has a certain appearance, but has a dissimilar appearance when in mid-heaven, and the same body one appearance in a wood and another in open country. The image again varies according to the position of the object, and a dove’s neck according to the way it is turned. Since, then, it is not possible to observe these things apart from places and positions, their real nature is unknowable.

The eighth mode is concerned with quantities and qualities of things, say heat or cold, swiftness or slowness, colourlessness or variety of colours. Thus wine taken in moderation strengthens the body, but too much of it is weakening; and so with food and other things.

The ninth mode has to do with perpetuity, strangeness, or rarity. Thus earthquakes are no surprise to those among whom they constantly take place; nor is the sun, for it is seen every day.[*](As contrasted, e.g., with a comet; cf. Sext. Emp. Pyrrh. Hyp. i. 141.) This ninth mode is put eighth by Favorinus and tenth by Sextus and Aenesidemus; moreover the tenth is put eighth by Sextus and ninth by Favorinus.

The tenth mode rests on inter-relation, e.g. between light and heavy, strong and weak, greater and less, up and down. Thus that which is on the right is not so by nature, but is so understood in virtue of its position with respect to something else; for, if that change its position, the thing is no longer on the right.

Similarly father and brother are relative terms, day is relative to the sun, and all things relative to our mind. Thus relative terms are in and by themselves unknowable. These, then, are the ten modes of perplexity.

But Agrippa and his school add to them[*](Sext. Emp. Pyrrh. Hyp. i. 37 ὄγδοος ὁ ἀπὸ τοῦ πρός τι. The intention of Agrippa was to replace the ten modes by his five.) five other modes, resulting respectively from disagreement, extension ad infinitum, relativity, hypothesis and reciprocal inference. The mode arising from disagreement proves, with regard to any inquiry whether in philosophy or in everyday life, that it is full of the utmost contentiousness and confusion. The mode which involves extension ad infinitum refuses to admit that what is sought to be proved is firmly established, because one thing furnishes the ground for belief in another, and so on ad infinitum.

The mode derived from relativity declares that a thing can never be apprehended in and by itself, but only in connexion with something else. Hence all things are unknowable. The mode resulting from hypothesis arises when people suppose that you must take the most elementary of things as of themselves entitled to credence, instead of postulating them: which is useless, because some one else will adopt the contrary hypothesis. The mode arising from reciprocal inference is found whenever that which should be confirmatory of the thing requiring to be proved itself has to borrow credit from the latter, as, for example, if anyone seeking to establish the existence of pores on the ground that emanations take place should take this (the existence of pores) as proof that there are emanations.[*](This is what is commonly called arguing in a circle.)

They would deny all demonstration, criterion, sign, cause, motion, the process of learning, coming into being, or that there is anything good or bad by nature. For all demonstration, say they, is constructed out of things either already proved or indemonstrable. If out of things already proved, those things too will require some demonstration,

Nor must we prove that the elements are four from the fact that the elements are four. Besides, if we discredit particular demonstrations, we cannot accept the generalization from them. And in order that we may know that an argument constitutes a demonstration, we require a criterion; but again, in order that we may know that it is a criterion we require a demonstration; hence both the one and the other are incomprehensible, since each is referred to the other. How then are we to grasp the things which are uncertain, seeing that we know no demonstration? For what we wish to ascertain is not whether things appear to be such and such, but whether they are so in their essence.

They declared the dogmatic philosophers to be fools, observing that what is concluded ex hypothesi is properly described not as inquiry but assumption, and by reasoning of this kind one may even argue for impossibilities.

As for those who think that we should not judge of truth from surrounding circumstances or legislate on the basis of what is found in nature, these men, they used to say, made themselves the measure of all things, and did not see that every phenomenon appears in a certain disposition and in a certain reciprocal relation to surrounding circumstances. Therefore we must affirm either that all

Therefore it is impossible to pronounce judgement on opinions about sensibles or intelligibles; and if the conflict in our thoughts compels us to disbelieve every one, the standard or measure, by which it is held that all things are exactly determined, will be destroyed, and we must deem every statement of equal value. Further, say they, our partner in an inquiry into a phenomenon is either to be trusted or not. If he is, he will have nothing to reply to the man to whom it appears to be the opposite[*](e.g. to be not a serpent, but a coil of rope.); for just as our friend who describes what appears to him is to be trusted, so is his opponent. If he is not to be trusted, he will actually be disbelieved when he describes what appears to him.

We must not assume that what convinces us is actually true. For the same thing does not convince every one, nor even the same people always. Persuasiveness sometimes depends on external circumstances, on the reputation of the speaker,

on his ability as a thinker or his artfulness, on the familiarity or the pleasantness of the topic.

Again, they would destroy the criterion by reasoning of this kind. Even the criterion has either been critically determined or not. If it has not, it is definitely untrustworthy, and in its purpose of distinguishing is no more true than false. If it has, it will belong to the class of particular judgements, so that one and the same thing determines and is determined, and the criterion which has determined will have to be determined by another, that other by another, and so on ad infinitum.

In addition to this there is disagreement as to the criterion, some holding that man is the criterion, while for some it is the senses, for others reason, for others the apprehensive presentation. Now man disagrees with man and with himself, as is shown by differences of laws and customs. The senses deceive, and reason says different things. Finally, the apprehensive presentation is judged by the mind, and the mind itself changes in various ways. Hence the criterion is unknowable, and consequently truth also.

They deny, too, that there is such a thing as a sign. If there is, they say, it must either be sensible or intelligible. Now it is not sensible, because what is sensible is a common attribute, whereas a sign is a particular thing. Again, the sensible is one of the things which exist by way of difference, while the sign belongs to the category of relative. Nor is a sign an object of thought, for objects of thought are of four kinds, apparent judgements on things apparent, non-apparent judgements on things nonapparent, non-apparent on apparent, or apparent on non-apparent; and a sign is none of these, so

nor, lastly, is it apparent on non-apparent, because the sign, being relative, must be apprehended along with that of which it is the sign, which is not here the case. It follows that nothing uncertain can be apprehended; for it is through signs that uncertain things are said to be apprehended.[*](This conclusion would debar us from all extension of knowledge beyond what is apparent here and now; whereas the dogmatists permit us from such facts to advance to what is not immediately evident, the realm of the unknown or as yet unascertained (ἄδηλον).).

Causes, too, they destroy in this way. A cause is something relative; for it is relative to what can be caused, namely, the effect. But things which are relative are merely objects of thought and have no substantial existence.

Therefore a cause can only be an object of thought; inasmuch as, if it be a cause, it must bring with it that of which it is said to be the cause, otherwise it will not be a cause. Just as a father, in the absence of that in relation to which he is called father, will not be a father, so too with a cause. But that in relation to which the cause is thought of, namely the effect, is not present; for there is no coming into being or passing away or any other process: therefore there is no such thing as cause. Furthermore, if there is a cause, either bodies are the cause of bodies, or things incorporeal of things incorporeal; but neither is the case; therefore there is no such thing as cause. Body in fact could not be the cause of body, inasmuch as both have the same nature. And if either is

But if both be alike causes, there will be nothing to be acted upon Nor can an incorporeal thing be the cause of an incorporeal thing, for the same reason. And a thing incorporeal cannot be the cause of a body, since nothing incorporeal creates anything corporeal. And, lastly, a body cannot be the cause of anything incorporeal, because what is produced must be of the material operated upon; but if it is not operated upon because it is incorporeal, it cannot be produced by anything whatever. Therefore there is no such thing as a cause. A corollary to this is their statement that the first principles of the universe have no real existence; for in that case something must have been there to create and act.

Furthermore there is no motion; for that which moves moves either in the place where it is or in a place where it is not. But it cannot move in the place where it is, still less in any place where it is not. Therefore there is no such thing as motion.

They used also to deny the possibility of learning. If anything is taught, they say, either the existent is taught through its existence or the non-existent through its non-existence. But the existent is not taught through its existence, for the nature of existing things is apparent to and recognized by all; nor is the non-existent taught through the nonexistent, for with the non-existent nothing is ever done, so that it cannot be taught to anyone.

Nor, say they, is there any coming into being. For that which is does not come into being, since it is; nor yet that which is not, for it has no substantial