De primo frigido

Furthermore, we find that cold can be perceived

as well as heat; but mere negation cannot be seen or heard or touched or recognized by the other senses. Perception, in fact, must be of something existent; but where nothing existent is observed, privation may be inferred, being the negation of existence, as blindness is of sight, silence of sound, void and emptiness of matter. We cannot perceive a void by touch; but where no matter can be touched, void is inferred. Nor can we hear silence; yet, even though we hear nothing, we infer silence. Nor, in the same way, is sense active when things are unseen or bare[*](As, when a hill has been stripped of timber, you cannot see the trees.); there is, rather, inference from the negation of perception. If, therefore, cold were a privation of warmth, we ought not to be able to feel it, but only to infer it from the deficiency in warmth; but if cold is perceived by the contraction and condensation of our flesh (just as heat is by the warming and loosening of it), clearly there is some special first principle and source of coldness, just as there is of heat.

Is cold, then, so like this sort of privation that

it produces no effects that differ ? Or is the contrary true: Do not great and useful pleasures accrue to our bodies from the presence of cold, as well as mighty detriments and pains and depressions, before which the heat does not always depart and quit the field ? Often, rather, though cut off within, it makes a stand and gives battle. This struggle of hot and cold is called shivering or shaking; and if heat is overcome, freezing and torpor set in; but if cold is defeated, there is diffused through the body a relaxed and pleasantly warm sensation which Homer[*](See, e.g., Odyssey, vi. 156; Iliad, xxiii. 598, 600; and cf. Mor. 454 d, 735 f.) calls to be aglow. Surely these facts are obvious to everyone; and it is chiefly by these effects that cold is shown to be in opposition to heat, not as a negation or privation, but as one substance or one state[*](Heat, for example, may be said to be a state or condition of metal.) to another: it is not a mere destruction or abolition of heat, but a positive substance or force. Otherwise we might just as well exclude winter from the list of seasons or the northerly blasts from that of winds, on the pretext that they are only a deficiency of hot weather or southerly gales and have no proper origin of their own.

Furthermore, given four primary bodies in the universe[*](See Diels-Kranz, Frag. der Vorsok. 5, i, pp. 315 ff., Empedocles, frag. B 17. The doctrine is clearly stated by, for example, Pliny, Nat. Hist. ii. 10. The author of the Epinomis (981 c) adds a fifth element, aether (cf. 951 d infra).) which, because of their quantity, simplicity, and potentiality, most judges regard as being the elements or first principles of everything else - I mean fire, water, air, and earth - the number of primary, simple qualities must be the same. And what should these be but warmth and cold, dryness

and moisture, which by their very nature cause all the elements to act and be acted upon?[*](Post translates his emendation: by which all things are qualified through the natural action of the elements, pointing out that elements have nothing but size, shape, and motion. Fire causes heat, but its atoms are not themselves hot.) Just as in grammar we have elements long and short and in music elements high and low in pitch - and in neither case is one element merely a negation of the other - so also in physical bodies we must assume an elementary opposition of wet to dry and cold to hot, and in this way we shall be faithful both to logic and to experience. Or are we, as old Anaximenes[*](Diels-Kranz, Frag. der Vorsok. 5, i, p. 95; cf. Diller, Hermes, lxvii, pp. 35 f.) maintained, to leave neither hot nor cold in the realm of being, but to treat them as states belonging equally to any matter and occurring as a result of changes within it ? He affirms, in fact, that anything which undergoes contraction and condensation of matter is cold, while anything that suffers rarefaction and distention - this comes close to his own phrasing - is hot. So there is no contradiction in the remark that the man blew both hot and cold,[*](See Aesop’s Fables (no. 60 in Chambry’s Bude edition, vol. i, pp. 131 ff.), where the satyr renounces friendship with the man because the latter blows both hot and cold through the same mouth.) for breath grows cold when it is compressed and condensed by the lips; but when it is expelled from the mouth left slack, it becomes hot through rarefaction. Aristotle,[*](Probably (cf. the note on 950 b infra) Problemata, xxxiv. 7 (964 a 10 ff.); contrast Plato, Timaeus, 79 a-c.) however, holds that in this Anaximenes was mistaken: when the mouth is slack, what is exhaled is warm air from our own bodies; but when we compress the lips and blow, it is not air from ourselves, but the cold air in front of the mouth that is propelled forward and makes contact.