Complete Works of Plutarch — Volume 3 · Plutarch
CHAPTER XII. OF BODIES.
A body is that being which hath these three dimensions, breadth, depth, and length;--or a bulk which makes a sensible resistance;--or whatsoever of its own nature possesseth a place. Plato saith that it is neither heavy nor light in its own nature, when it exists in its own place; but being in the place where another should be, then it has an inclination by which it tends to gravity or levity. Aristotle saith that, if we simply consider things in their own nature, the earth only is to be judged heavy, and fire light; but air and water are on occasions heavy and at other times light. The Stoics think that of the four elements two are light, fire and air; two ponderous, earth and water; that which is naturally light doth by its own nature, not by any inclination, recede from its own centre; but that which is heavy doth by its own nature tend to its centre; for the centre is not a heavy thing in itself. Epicurus thinks that bodies are not limited; but the first bodies, which are simple bodies, and all those composed of them, all acknowledge gravity; that all atoms are moved, some perpendicularly, some obliquely; some are carried aloft either by immediate impulse or with vibrations. CHAPTER XIII. OF THOSE THINGS THAT ARE LEAST IN NATURE.
Empedocles, before the four elements, introduceth the most minute bodies which resemble elements; but they did exist before the elements, having similar parts and orbicular. Heraclitus brings in the smallest fragments, and those indivisible. A figure is the exterior appearance, the circumscription, and the boundary of a body. The Pythagoreans say that the bodies of the four elements are spherical, fire being in the supremest place only excepted, whose figure is conical. Color is the visible quality of a body. The Pythagoreans called color the external appearance of a body. Empedocles, that which is consentaneous to the passages of the eye. Plato, that they are fires emitted from bodies, which have parts harmonious for the sight. Zeno the Stoic, that colors are the first figurations of matter. The Pythagoreans, that colors are of four sorts, white and black, red and pale; and they derive the variety of colors from the mixtures of the elements, and that seen in animals also from the variety of food and the air. The disciples of Thales and Pythagoras grant that all bodies are passible and divisible into infinity. Others hold that atoms and indivisible parts are there fixed, and admit not of a division into infinity. Aristotle, that all bodies are potentially but not actually divisible into infinity. CHAPTER XVII. HOW BODIES ARE MIXED AND CONTEMPERATED ONE WITH ANOTHER.
The ancient philosophers held that the mixture of elements proceeded from the alteration of qualities; but the disciples of Anaxagoras and Democritus say it is done by apposition. Empedocles composes the elements of still minuter bulks, those which are the most minute and may be termed the element of elements. Plato assigns three bodies (but he will not allow these to be elements, nor properly so called), air, fire, and water, which are mutable into one another; but the earth is mutable into none of these. All the natural philosophers from Thales to Plato rejected a vacuum. Empedocles says that there is nothing of a vacuity in Nature, nor anything superabundant. Leucippus, Democritus, Demetrius, Metrodorus, Epicurus, that the atoms are in number infinite; and that a vacuum is infinite in magnitude. The Stoics, that within the compass of the world there is no vacuum, but beyond it the vacuum is infinite. Aristotle, that the vacuum beyond the world is so great that the heaven has liberty to breathe into it, for the heaven is fiery. Plato, to define place, calls it that thing which in its own bosom receives forms and ideas; by which metaphor he denotes matter, being (as it were) a nurse or receptacle of beings. Aristotle, that it is the ultimate superficies of the circumambient body, contiguous to that which it doth encompass.
The Stoics and Epicureans make a place, a vacuum, and space to differ. A vacuum is that which is void of anything that may be called a body; place is that which is possessed by a body; a space that which is partly filled with a body, as a cask with wine. In the sense of Pythagoras, time is that sphere which encompasses the world. Plato says that it is a movable image of eternity, or the interval of the world's motion. Eratosthenes, that it is the solar motion. CHAPTER XXII. OF THE SUBSTANCE AND NATURE OF TIME. Plato says that the heavenly motion is time. Most of the Stoics that motion is time. Most philosophers think that time had no commencement; Plato, that time had only in intelligence a beginning. Plato and Pythagoras say that motion is a difference and alteration in matter. Aristotle, that it is the actual operation of that which may be moved. Democritus, that there is but one sort of motion, and it is that which is vibratory. Epicurus, that there are two species of motion, one perpendicular, and the other oblique. Herophilus, that one species of motion is obvious only to reason, the other to sense. Heraclitus utterly denies that there is anything of quiet or repose in nature; for that is the state of the dead; one sort of motion is eternal, which he assigns to beings eternal, the other perishable, to those things which are perishable.
Ideas discussed in this chapter
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