For an idea that does not first seem insane, there is no hope.

Imagination is the highest form of research.

Dr. Einstein: Yes; But this year the answers are different.

In my relativity theory I set up a clock at every point in space, but in reality I find it difficult to provide even one clock in my room.

Gradually the conviction gained recognition that all knowledge about things is exclusively a working-over of the raw material furnished by the senses. ... Galileo and Hume first upheld this principle with full clarity and decisiveness.

Honestly, I cannot understand what people mean when they talk about the freedom of the human will. I have a feeling, for instance, that I will something or other; but what relation this has with freedom I cannot understand at all. I feel that I will to light my pipe and I do it; but how can I connect this up with the idea of freedom? What is behind the act of willing to light the pipe ? Another act of willing?

The illusion that we are separate from one another is an optical delusion of our consciousness.