Samuel Clarke (1675–1729) profoundly shaped early eighteenth-century European philosophy with an a priori demonstration of the existence of God and influential defenses of substance dualism and human freedom. Throughout his works, he defended absolute space, the passivity of matter, and constant divine activity in the world, which jointly provided a metaphysical basis for the quickly popularizing Newtonian thought.

Anthony Collins (1676-1729) maintains that consciousness might be a material process or result from material processes. On the one hand, Collins accepts Locke’s view that from consciousness, i.e., the activity of thinking, we acquire no knowledge about the nature of the thinking substance. On the other, he takes seriously Samuel Clarke’s challenge that the thinking substance must be suitably unified because consciousness is unified. In this paper, I argue that, throughout his correspondence with Clarke, Collins maintains that consciousness signifies actual (...) thinking and does not refer to the capacity of thinking. His main materialist thesis is that the powers of parts of material systems can bring about unified powers and that the power of thinking may be such a power. Collins attempts to satisfy the unity requirement by arguing that a unity correspondence can obtain between consciousness and the power of thinking that is realized in a material composite. (shrink)

Locke’s argument for God’s immateriality in _Essay_ IV x is usually interpreted as involving a principle that in some way prohibits the causation of thought by matter. I reject these causal readings in favor of one that involves a principle which says a thinking being cannot be composed out of unthinking parts. This Composition Principle, as I call it, is crucial to understanding how Locke’s theistic argument can succeed in the face of his skepticism about the substance of matter and (...) the cause of thought, as well as his belief in the possibility of thinking matter. It also explains why Locke held the soul’s immateriality to be highly probable. (shrink)