exclusive and to substitute it for natural philosophy. Locke, who was
himself a medical man, knew what a black cloak for ignorance and villainy
Scholastic verbiage might be in that profession. He also knew, being an
enthusiast for experimental science, that in order to control the movement
of matter--which is to realise those virtues and perfections--it is better
to trace the movement of matter materialistically; for it is in the act of
manifesting its own powers, and not, as Socrates and the Scholastics
fancied, by obeying a foreign magic, that matter sometimes assumes or
restores the forms so precious in the healer's or the moralist's eyes. At
the same time, the manner in which the moral world rests upon the natural,
though divined, perhaps, by a few philosophers, has not been generally
understood; and Locke, whose broad humanity could not exclude the moral
interpretation of nature, was driven in the end to the view of Socrates.
He seriously invoked the Scholastic maxim that nothing can produce that
which it does not contain. For this reason the unconscious, after all,
could never have given rise to consciousness. Observation and experiment
could not be allowed to decide this point: the moral interpretation of
things, because more deeply rooted in human experience, must envelop the
physical interpretation, and must have the last word.

It was characteristic of Locke's simplicity and intensity that he retained
these insulated sympathies in various quarters. A further instance of his
many-sidedness was his fidelity to pure intuition, his respect for the
infallible revelation of ideal being, such as we have of sensible
qualities or of mathematical relations. In dreams and in hallucinations
appearances may deceive us, and the objects we think we see may not exist
at all. Yet in suffering an illusion we must entertain an idea; and the
manifest character of these ideas is that of which alone, Locke thinks, we
can have certain "knowledge".