d substance. The two are thus simply disparate realities, with no vital connection between them. This is significantly marked by his theory of the soul's location in the body. Unlike the Scholastics he confines it to a single point -- the pineal gland -- from which it is supposed to control the various organs and muscles through the medium of the "animal spirits", a kind of fluid circulating through the body. Thus, to say the least, the soul's biological functions are made very remote and indirect, and were in fact later on reduced almost to a nullity: the lower life was violently severed from the higher, and regarded as a simple mechanism. In the Cartesian theory animals are mere automata. It is only by the Divine assistance that action between soul and body is possible. The Occasionalists went further, denying all interaction whatever, and making the correspondence of the two sets of facts a pure result of the action of God. The Leibnizian theory of Pre-established Harmony similarly refuses to admit any inter-causal relation. The superior monad (soul) and the aggregate of inferior monads which go to make up the body are like two clocks constructed with perfect art so as always to agree. They register alike, but independently: they are still two clocks, not one. This awkward Dualism was entirely got rid of by Spinoza. For him there is but one, infinite substance, of which thought and extension are only attributes. Thought comprehends extension, and by that very fact shows that it is at root one with that which it comprehends. The alleged irreducible distinction is transcended: soul and body are neither of them substances, but each ...
