Whatever we know without inference is mental.

It is entirely clear that there is only one way in which great wars can be permanently prevented, and that is the establishment of an international government …

I do not believe that I am now dreaming, but I cannot prove that I am not. I am, however, quite certain that I am having certain experiences, whether they be t…

Aristotle, as a philosopher, is in many ways very different from all his predecessors. He is the first to write like a professor: his treatises are systematic,…

Truth lies within a little and certain compass, but error is immense.

We cannot observe external things without some degree of Thought; nor can we reflect upon our Thoughts, without being influenced in the course of our reflectio…

Knowing reality means constructing systems of transformations that correspond, more or less adequately, to reality. They are more or less isomorphic to transfo…