ing reflective powers in nowise
remarkable, have independently arrived at the conception that the mind
is a nonextended and immaterial substance? Surely they have not
thought all this out for themselves. They have taken up and
appropriated unconsciously notions which were in the air, so to speak.
They have inherited their doctrines, not created them. It is well to
remember this, for it may make us the more willing to take up and
examine impartially what we have uncritically turned into articles of
belief.

The first two articles, namely, that the mind is in the body and that
it acts upon, and is acted upon by, material things, I shall discuss at
length in the next chapter. Here I pause only to point out that the
plain man does not put the mind into the body quite unequivocally. I
think it would surprise him to be told that a line might be drawn
through two heads in such a way as to transfix two minds. And I
remark, further, that he has no clear idea of what it means for mind to
act upon body or body to act upon mind. How does an immaterial thing
set a material thing in motion? Can it touch it? Can it push it?
Then what does it do?

But let us pass on to the last two articles of faith mentioned above.

We all draw the distinction between _substance_ and its _attributes_ or
_qualities_. The distinction was remarked and discussed many centuries
ago, and much has been written upon it. I take up the ruler on my
desk; it is recognized at once as a bit of wood. How? It has such and
such qualities. My paper-knife is of silver. How do I know it? It
has certain other qualities. I speak of my mind. How do I know that I
have a mind? I have sensations and ideas. If I experienced no mental
phenomena of any sort, evidence of the existence of a mind would be
lacking.

Now, whether I am concerned with the ruler, with the paper-knife, or
with the mind, have I direct evidence of the existence of anything more
than the whole group of qualities? Do I ever perceive the substance?

In the older philosophy, the substance (_substantia_) was conceived to
be a something not directly perceived, but only inferred to exist--a
something underlying the qualities of things and, as it were, holding
them together. It was believed in by philosophers who were quite ready
to admit that they could not tell anything about it. For example, John
Locke (1632-1704), the English philosopher, holds to it stoutly, and
yet describes it as