when followed out, is, after all, formal rather than sub-
stantive; for, in either case, the Vital Principle, whether
like or unlike, must be material, as the opinion still
implies some kind of impression, and impression implies
material properties.
Note 4, p. 49. But to shew how many doubts, &c.]
The earlier philosophers differed widely, as has been said,
upon the elements, both as to their nature and number;
but those writers are evidently wrong, Aristotle[1] observes,
who admit of only one element and one nature, as they
take no account of incorporeal entities. Empedocles
adopted the four elements as constitutive of the matter of
bodies, and hence the objection to his opinion, that "sen-
sation is produced by corporeal elements in the relation
of like;" for those parts which are formed of earth (hair,
bones, &c.) are insensible; and, therefore, this element
cannot be perceptive of like. This assumption of insen-
sibility is, of course, too absolute, but such parts are no
doubt withdrawn, more or less, from the general sensi-
bility and sympathy of the living body. The term νεῦρα,
it may be observed, by the way, which here signifies
tendon or sinew, has now the meaning of nerves, the
conductors, that is, of sentient impressions; and Galen,
who lived so many ages after Aristotle, and was well
acquainted with the brain, optic nerves, and office of the
nerves, still employed νεῦρον as a muscular chord.
- ↑ Metaphys. I. 8. I; XIII. 4, 5.
