As the metaphysical writings of Aristotle and his followers are likely to be but little known to the majority of modern readers, it may be useful to add a brief account of the ancient method of treating the subject, which will serve at the same time to exhibit more clearly the chasm which separates the earlier conception of the science from that of the modern disciple of Locke or Stewart. “ There is a certain science,” says Aristotle, “ which contemplates Being in so far as it is Being, and the attributes that belong to it essentially as such.
This science is not the same with any of those which are called particular sciences; for none of these inquires generally concerning Being as Being, but each selects some separate portion of Being, and contemplates the properties of that alone; as, for example, mathematics. But since we are seeking for the principles and highest causes of tilings, it is clear that these must have some nature to which they properly belong.
What is the relation of self-evidence to reality? Is the necessity, of which I am conscious, of thinking in a certain manner, any sure guarantee of a corresponding relation in the objects about which I think ? In other words, are the laws of thought also laws of things; or, at least, do they furnish evidence by which the laws of things can be ascertained?
Is thought identical with being, so that every mode of the one is at the same time a mode of the other? Is thought an exact copy of being, so that every mode of the one is an adequate representative of some corresponding mode of the other?
Or, finally, is thought altogether distinct from being, so that we cannot issue from the circle of our ideas, to seize the realities which those ideas are supposed to represent? Does anything exist beyond the phenomena of our own consciousness? And, if it does exist, what is phenomena of Thought.
***Excerpt from Henry Longueville Mansel, B.d.. Metaphysics or the philosophy of consciousness