But, on the other hand, we may ask: How do we come to infer this or that thought from this or that action of another?
The only reply is: Because when we act in the same way this is the way we feel.

So we get back in any case to our own consciousness and must ask how is this action related to this thought in our own mind.
To this question psychology has now a general answer: Our action is always the result of our thought, of the elements of knowledge which are at the time present in the mind.

Of course, there are actions which we do from purely nervous reasons.

These are the Instincts, which come up again when we consider the animals.

But these we may neglect so long as we are investigating actions which we consider our own.