of the physical world, though not matter in the sense of
physics. Thus the whole question of the relation of mental occurrences
to objects grows very complicated, and cannot be settled by regarding
reference to objects as of the essence of thoughts. All the above
remarks are merely preliminary, and will be expanded later.

Speaking in popular and unphilosophical terms, we may say that the
content of a thought is supposed to be something in your head when you
think the thought, while the object is usually something in the outer
world. It is held that knowledge of the outer world is constituted by
the relation to the object, while the fact that knowledge is different
from what it knows is due to the fact that knowledge comes by way of
contents. We can begin to state the difference between realism and
idealism in terms of this opposition of contents and objects. Speaking
quite roughly and approximately, we may say that idealism tends to
suppress the object, while realism tends to suppress the content.
Idealism, accordingly, says that nothing can be known except thoughts,
and all the reality that we know is mental; while realism maintains that
we know objects directly, in sensation certainly, and perhaps also in
memory and thought. Idealism does not say that nothing can be known
beyond the present thought, but it maintains that the context of vague
belief, which we spoke of in connection with the thought of St. Paul's,
only takes you to other thoughts, never to anything radically different
from thoughts. The difficulty of this view is in regard to sensation,
where it seems as if we came into direct contact with the outer world.
But the Berkeleian way of meeting this difficulty is so familiar that I
need not enlarge upon it now. I shall return to it in a later lecture,
and will only observe, for the present, that there seem to me no valid
grounds for regarding what we see and hear as not part of the physical
world.

Realists, on the other hand, as a rule, suppress the content, and
maintain that a thought consists either of act and object alone, or of
object alone. I have been in the past a realist, and I remain a realist
as regards sensation, but not as regards memory or thought. I will try
to explain what seem to me to be the reasons for and against various
kinds of realism.

Modern idealism professes to be by no means confined to the present
thought or the present thinker in regard to its knowledge; indeed, it
contends