Will, Parallelism, Causality

Spinoza's Parallelism entails not only the simultaneity of the mental and the corporeal sequences, but their non-communication, as well. In other words, it entails, for example, that Mind is never the origin of Motility, which, he suggests, always has a physical cause, even if the mechanism involved remains undiscovered. In contrast, here, that explanation is not adequate enough to override the plain and familiar evidence that one can initiate a physiological process with a mental command, i. e. that Will, the principle of Motility in Experience, originates mentally and eventuates physiologically. Furthermore, Spinoza leaves unexamined how, in either sequence, one and the same element in the concatenation can be both cause and effect, i. e. can be first the effect of a prior cause, and then the cause of a subsequent effect. In contrast, here, a fundamental significance of the distinction between cause and effect is that the former initiates a sequence, while the latter terminates it, an irreducible distinction that is derived from that of the two principles of Experience, Will and Comprehension, respectively. So, insofar, as each of Spinoza's two sequences are causal concatenations, his Parallelism of Body and Mind presupposes, and abstracts from, a more fundamental interaction of the two.