On the Principle of Cold (15-19)

It is reasonable that the lower portion of large rivers should not freeze; for the upper portion, being frozen, does not transmit the exhalation which is, accordingly, shut in and turned back, and so provides heat for the deep waters. A demonstration of this is the fact that when the ice melts again a great quantity of vapour rises from the waters. This is also the reason why the bodies of animals are warmer in the winter, because the heat is driven inwards by the cold from without and they keep it within them.

Now drawing off water and suspending it in the air[*] not only takes away its warmth, but its coldness also; those, therefore, who want a very cold drink take care not to disturb the snowpacks[*] or the wet matter that is formed from them by compression, for movement expels both heat and cold.

That such a function of cold belongs not to air, but to water, may be demonstrated as follows from a fresh

start. In the first place, it is improbable that air, which lies adjacent to the aether[*] and touches and is touched by the revolving fiery substance, should have a force that is contrary to that of aether. For one thing, it is impossible for two substances whose boundaries touch and are contiguous not to be acted upon by each other - and if acted upon, for the weaker not to be contaminated by the force that resides in the stronger. Nor is it reasonable to suppose that Nature has placed side by side destroyer and victim, as though she were the author of strife and dissension, not of union and harmony. She does, indeed, make use of opposites to constitute the universe; yet she does not employ them without a tempering element, or where they will collide. She disposes them rather so that a space is skipped and an inserted strip duly assigned whereby they will not destroy one another, but may enjoy communication and co-operation. And this strip is occupied by air, suffused as it is through a space under the fire[*] between it and water. It makes distribution both ways and receives contributions from both, being itself neither hot nor cold, but a blending and union of the two. When these are so fused, they meet without injury and the fused matter sends forth or takes to itself the opposing extremes[*] without violence.

Then, too, air is everywhere equal; though neither winter nor cold is identical everywhere. It is no accident that some parts of the world are cold and damp, while others are hot and dry; it is due to the existence of a single substance that includes

coldness and wetness in one. The greater part of Africa is hot and without water; while those who have travelled through Scythia, Thrace, and Pontus[*] report that these regions have great lakes or marshes and are traversed by many deep rivers. As for the regions that lie between, those that are near lakes and marshes are especially cold because of the exhalations from the water, Posidonius,[*] then, in affirming that the freshness and moistness of marsh air is the reason for the cold, has done nothing to disturb the plausibility of the argument; he has, rather, made it more plausible. For fresh air would not always seem colder if cold did not take its origin from moisture. So Homer[*] spoke more truly when he affirmed

The river-air blows chill before the dawn,

thereby indicating the source of coldness.

Our senses, moreover, often deceive us and we imagine, when we touch cold garments or cold wool, that we are touching moist objects: this is because wet and cold have a common substance and their natures have a close affinity and relationship. In very cold climates the low temperature often breaks vessels whether they are of bronze or of clay - not, of course, when they are empty, but only when they are full and the water exerts pressure by means of its coldness. Theophrastus,[*] to be sure, declares that the air breaks these vessels, using the liquid as a spike. But take care[*] that there isn’t more wit than

truth in such a remark! For if it were so, vessels full of pitch or of milk would more readily be broken by the air.[*]

Water, however, seems to be cold of itself, and primordially so. It is the antithesis, in its coldness, to the heat of fire, just as in its wetness to the dryness of fire, and in its heaviness to the other’s lightness. To sum up: fire is of a disintegrating and separative nature, while water is adhesive and retentive, holding and gluing together by means of its moistness. Empedocles[*] alluded to this, when, as often as he mentioned them, he termed Fire a Destructive Strife and Water Tenacious Love. For the nourishment of fire is that which can be changed into fire and only things that have affinity and a close relationship to it can be so changed; while its opposites, like water, are not easily changed to fire. Water itself is practically incombustible, and it renders matter such as damp grass and moist timber very hard to consume; the greenness in them produces a dusky, dull flame because, by dint of cold, it struggles against heat as against its natural enemy.

Now you must pursue the subject by comparing these arguments with those of my opponents. For Chrysippus,[*] thinking that the air is primordially cold because it is also dark, merely mentioned those who affirm that water is at a greater distance from the aether[*] than is air; and, wishing to make them some answer, he said, If so, we might as well declare that even earth is primordially cold because it is at the

greatest distance from the aether - tossing off this argument as if it were utterly inadmissible and absurd. But I have a mind to maintain the thesis that earth too is not destitute of probable and convincing arguments, and I shall start with the one that Chrysippus has found most serviceable for air. And what is this ? Why, that it is primordially dark and cold. For if he takes these two pairs of opposing forces and assumes that one must of necessity accompany the other, there are, surely, innumerable oppositions and antipathies between the aether and the earth with which one might suppose this to be consistent. For it is not only opposed as heavy to light and as moving by gravity downwards, not upwards, or as dense to rare or as slow and stable to mobile and active, but as heaviest to lightest and as densest to rarest and, finally, as immovable of itself to self-moving, and as occupying the central position in the universe to revolving forever around a centre. It is not absurd, then, if oppositions so numerous and important carry with them the opposition of cold and heat as well. Yes, Chrysippus may say, but fire is bright. Is not the earth, then, dark ? Why, it is the darkest and most unilluminated of all things. Certainly air is first of all to participate in light; it is instantly altered and when it is saturated, it distributes illumination everywhere, lending itself to light as a body in which to reside. For when the sun arises, as one of the dithyrambic writers[*] has said,

It straightway fills the mighty home of the air-borne winds.

Next the air, moving downward, infuses a part of its brightness into the lakes and the sea, and the depths of the rivers flash brightly,[*] to the extent that air is able to penetrate them. Of all bodies only the earth remains constantly without light, impenetrable to the illumination of sun or moon; yet it is warmed by them and permits the heat to sink in and warm it up to a slight depth. But because it is solid, earth does not give passage to light, but is encircled by light on its surface only, while the inner parts are called Darkness and Chaos and Hades[*] - so that Erebus[*] turns out to be the subterranean and interior darkness. Then, too, the poets tell us that Night was born of Earth[*] and mathematicians demonstrate that night is the shadow of Earth blocking the light of the sun. The air, indeed, is saturated with darkness by the earth, just as it is with light by the sun. The unlighted portion of the air is the area of night, amounting to the space occupied by the earth’s shadow. This is the reason why men make use of the air out of doors even when it is night, as well as many beasts which do their pasturing in the darkness, since it retains some vestiges of light and dispersed glimmerings of radiance; but the house-bound man who is under a roof is utterly blind and without light inasmuch as there the earth envelops him from all directions. Whole skins, furthermore, and horns of animals do not let light pass through them because of their solidity; yet if sections are sawed off and polished, they become translucent when once the air has been mixed with them. It is also my opinion that the earth is called black by the poets,[*] whenever they have occasion to do so, because of its murky and lightless characteristics. The result, then, of these considerations is that the much-prized antithesis of light and darkness belongs to earth rather than to air.

This, however, has no relevance to the question under discussion; for it has been shown that there are many cold objects which are bright and many hot which are dull and dark. Yet there are qualities more closely connected that belong to coldness: heaviness, stability, solidity, and resistance to change. Air has no part at all in them, while earth has a greater share in all of them than water has. Cold, moreover, is perceptibly one of the hardest of things and it makes things hard and unyielding. Theophrastus,[*] for instance, tells us that when frozen fish are dropped on the ground, they are broken and smashed to bits just like objects of glass or earthenware. And at Delphi you yourself heard, in the case of those who climbed Parnassus to rescue the Thyiades[*] when they were trapped by a fierce gale and snowstorm, that their capes were frozen so stiff and wooden that when they were opened out, they broke and split apart. Excessive cold, because of its hardness and immobility, also stiffens the muscles and renders the tongue speechless, for it congeals the moist and tender parts of the body.

In view of these considerations, regard the facts in the following light: every force, presumably, whenever it prevails, by a law of nature changes and turns into itself whatever it overcomes. What is mastered by heat is reduced to flames, what is mastered by wind turns to air; and anything that falls into the water, unless it gets out quickly, dissolves and liquefies. It follows, then, that whatever is completely frozen must turn into primordial cold. Now freezing is extreme refrigeration that terminates in a complete alteration and petrifaction when, since the cold has obtained complete mastery, the moist elements are frozen solid and the heat is squeezed out. This is the reason why the earth at its bottommost point is practically all solid frost and ice. For there undiluted and unmitigated cold abides at bay, thrust back to the point farthest removed from the flaming aether.[*] As for these features that are visible, cliffs and crags and rocks, Empedocles[*] thinks that they have been fixed in place and are upheld by resting on the fire that burns in the depths of the earth; but the indications are rather that all these things from which the heat was squeezed out and evaporated were completely frozen by the cold; and for this reason they are called pagoi.[*] So also the peaks[*] of many of them have a black crust where the heat has been expelled and have the appearance of debris from a conflagration. For the cold freezes substances to a varying degree, but hardest those of which it is naturally a primary constituent. Thus, if

it is the nature of heat to lighten, the lightest object will have most heat, and if it is the nature of humidity to soften, the softest will have the most humidity; so, if it is also true that the nature of cold is to harden, then it must also follow that the hardest object will have the most cold - that is to say, just as the earth has. But what is coldest by nature is surely also primarily cold, so that the earth is in fact cold both primordially and naturally; and, of course, this is obvious even to the senses. Mud, in fact, is a colder thing than water; and men extinguish a fire by dumping earth upon it. Blacksmiths, when their iron becomes fiery and begins to melt, sprinkle on it marble chips and gypsum to check and cool it off before it melts too much. It is also true that dust cools the bodies of athletes and dries up their sweat.