This view betrays a complete misapprehension of the immaterial nature of psychical states as opposed to those of the body -- to say nothing of the childish notion of sense-perception, which modern physiology can regard only with an indulgent smile.
Epicurean Materialism received poetic expression and further development in the didactic poem of the Roman Lucretius.
As the word itself signifies, Materialism is a philosophical system which regards matter as the only reality in the world, which undertakes to explain every event in the universe as resulting from the conditions and activity of matter, and which thus denies the existence of God and the soul.
It is diametrically opposed to Spiritualism and Idealism, which, in so far as they are one-sided and exclusive, declare that everything in the world is spiritual, and that the world and even matter itself are mere conceptions or ideas in the thinking subject.
He says: "When the flavour of the wine vanishes, or the odour of the ointment passes away in the air, we notice no diminution of weight.
Even so with the body when the soul has disappeared." He overlooks the fact that the flavour and odour are not necessarily lost, even though we cannot measure them.
This last deduction is not warranted, since, even in infinite space, the bodies might be limited in number -- in fact, they must be, as otherwise they would entirely fill space and therefore render movement impossible.
Epicurus further asserted that bodies alone exist; only the void is incorporeal.
He distinguished, however, between compound bodies and simple bodies or atoms, which are absolutely unchangeable.
The soul ( anima ) and the mind ( animus ) consist of the smallest, roundest, and most mobile atoms.
That "feeling is an excitement of the atoms ", he lays down as a firmly established principle.