a term used by philosophers to denote the original component parts of bodies, or those into which they are ultimately resolvable.

Some of the ancients represented the elements as corruptible, and some as incorruptible. Those who maintained the incorruptibility of the elements, supposed them to be atoms, i.e., bodies which could not be divided, or broke into pieces. Of this opinion were Democritus, Epicurus, &c.

Among those who held the elements to be corruptible, some reckoned there was but one, and some that there were several elements. Heraclitus held fire, Anaximenes air, Thales Milesius water, and Hesiod earth, to be the only element. The Peripatetics contended for four elements, fire, air, earth, and water. Some of the philosophers considered only the sensible properties of bodies, such as pellucidity and opacity, to be elements. Of this number Aristotle himself is said to have been. For, considering the four principal qualities that fall under the sense of touch, he made four elements: the first, cold and dry; the second, cold and moist; the third, hot and moist; and the fourth, hot and dry. To give names to these elements, he inquired in what things these qualities were found chiefly to prevail. Accordingly, taking earth to be the coldest, and at the same time the driest of all things, he called the first element earth. Water being the coldest and moistest of all things, he called his second element water; and imagining air to be the hottest and moistest of all things, he called his third element air. Lastly, fire being the hottest and driest of all things, he called his fourth element fire.

The Cartesians admitted only of three elements, which they pretend were all that could arise from the first division of matter, the whole mass of which they supposed to have been from the beginning whirled round several different centres. The first element was composed of the angular parts and prominences broke off from the particles of matter by its continual motion. This was the materia subtilis. The second element was made up of the particles from which the materia subtilis was broke off, which were now become round; and the third element consisted of the particles which yet remained irregular.

Succeeding philosophers have differed greatly in their opinions; some adopting the Epicurean or atomical hypothesis, and some the Aristotelian. It is, however, easy to see, that the question concerning elements can never be solved. If we embrace the atomical system, we must be conscious that we know not what an atom is. We can have no idea of a body that doth not consist of parts, and consequently which cannot be made less than it is. If we adopt the notion of infinite divisibility, or, which is much the same, of the Aristotelian qualities, we shall find ourselves equally embarrassed. Some have imagined that there are two distinct elements, which they call the celestial and terrestrial matter. Both these they consider as made up of atoms; but they suppose the atoms of the first to be active, and of the second passive. It is difficult, however, to maintain this hypothesis without allowing one kind of atoms to be animated. Certain it is, that we see one part of matter in many cases acting upon, and giving motion to, another; but whether the matter which is passive in one case doth not become active in another, is a thing not easy to be determined. The utmost that can be said upon the subject seems to be, that as long as matter is subject to our eye-light and other senses, we can talk intelligibly about it; but when its parts become too small to be observed by them, we are then totally in the dark.

a figurative sense, is used for the principles and foundations of any art or science; as Euclid's Elements, &c.