Section 58. Sir William Hamilton's Dualism Is Developed in His

"Lectures on Metaphysics," VIII. He writes: "Mind and matter, as known or knowable, are only two different series of phenomena or qualities; as unknown and unknowable, they are the two substances in which these two different series of phenomena or qualities are supposed to inhere. The existence of an unknown substance is only an inference we are compelled to make, from the existence of known phenomena; and the distinction of two substances is only inferred from the seeming incompatibility of the two series of phenomena to coinhere in one."