philosophers. This question does not relate to the existence of the fact. The existence of the perception of matter is admitted on all hands. It refers to the nature, or origin, or constitution of the fact. Is the perception of matter simple and indivisible, or is it composite and divisible? Is it the ultimate, or is it only the penultimate, datum of cognition? Is it a relation constituted by the concurrence of a mental or subjective, and a material or objective element; or do we impose upon ourselves in regarding it as such? Is it a state or modification of the human mind? Is it an effect that can be distinguished from its cause? Is it an event consequent on the presence of real antecedent objects? These interrogations are somewhat varied in their form, but each of them embodies the whole point at issue, each of them contains the cardinal question of philosophy. The perception of matter is the admitted fact. The character of this fact, that is the point which speculation undertakes to canvass, and endeavours to decipher.
Another form in which the question may be put is this: We all believe in the existence of matter, but what kind of matter do we believe in the existence of? matter per se, or matter cum perceptione? If the former, this implies that the given fact (the perception of matter) is compound and submits to analysis; if the latter, this implies that it is simple and defies partition.
Opposite answers to this question are returned by psychology and metaphysic. In the estimation of
