§ 12. Physiological Dispositions.—In using such words as dispositions and traces, we have hitherto maintained a strictly psychological point of view. But as conscious process in general is correlated with nervous process, so psychological traces and dispositions may be regarded from another point of view as physiological facts. They are persistent modifications of nervous structure. Their existence, interconnexion, and mode of operation are in the first instance revealed to us by purely psychological evidence. But there are many advantages in also considering them from a physiological point of view. When we are considering a disposition merely as a trace of previous consciousness, and a precondition of further conscious process, we may call it a psychical disposition. "When, on the other hand, we desire to consider exclusively the physiological side, the term physiological disposition is in place. When both are simultaneously to be taken into account, it is appropriate to speak of a psychophysical disposition." *