23. A man begins to have ideas when he first has sensation.
What sensation is.
If it shall be demanded then, when
a man begins to have any ideas, I think the true answer is,--when he first has any sensation. For, since there
appear not to be any ideas in the mind before the senses have conveyed any in, I conceive that ideas in the
understanding are coeval with sensation; which is such an impression or motion made in some part of the body, as
produces some perception in the understanding. It is about these impressions made on our senses by outward
objects that the mind seems first to employ itself, in such operations as we call perception, remembering,
consideration, reasoning, etc.