city in trying to get to the bottom. Any ledge or obstacle will
stop it, and it will exhibit no signs of discontent if this happens. It
is not attracted by the pleasantness of the valley, as a sheep or cow
might be, but propelled by the steepness of the hill at the place
where it is. In all this we have characteristic differences between the
behaviour of animals and the behaviour of matter as studied by physics.

Desire, like knowledge, is, of course, in one sense an observable
phenomenon. An elephant will eat a bun, but not a mutton chop; a duck
will go into the water, but a hen will not. But when we think of our
own desires, most people believe that we can know them by an immediate
self-knowledge which does not depend upon observation of our actions.
Yet if this were the case, it would be odd that people are so often
mistaken as to what they desire. It is matter of common observation that
"so-and-so does not know his own motives," or that "A is envious of B
and malicious about him, but quite unconscious of being so." Such people
are called self-deceivers, and are supposed to have had to go through
some more or less elaborate process of concealing from themselves what
would otherwise have been obvious. I believe that this is an entire
mistake. I believe that the discovery of our own motives can only be
made by the same process by which we discover other people's, namely,
the process of observing our actions and inferring the desire which
could prompt them. A desire is "conscious" when we have told ourselves
that we have it. A hungry man may say to himself: "Oh, I do want my
lunch." Then his desire is "conscious." But it only differs from an
"unconscious" desire by the presence of appropriate words, which is by
no means a fundamental difference.

The belief that a motive is normally conscious makes it easier to be
mistaken as to our own motives than as to other people's. When some
desire that we should be ashamed of is attributed to us, we notice that
we have never had it consciously, in the sense of saying to ourselves,
"I wish that would happen." We therefore look for some other
interpretation of our actions, and regard our friends as very unjust
when they refuse to be convinced by our repudiation of what we hold to
be a calumny. Moral considerations greatly increase the difficulty of
clear thinking in this matter. It is commonly argued that people are not
to blame for unconscious motives, but only for conscious ones.