... on principle, it is quite wrong to try founding a theory on observable magnitudes alone. In reality the very opposite happens. It is the theory which decides what we can observe.

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.

Don't do anything that goes against your conscience, even if your country says so.

How was I able to live alone before, my little everything? Without you I lack self-confidence, passion for work, and enjoyment of life--in short, without you, my life is no life. [Written to his wife, Mileva]

A conflict arises when a religious community insists on the absolute truthfulness of all statements recorded in the Bible. This means an intervention on the part of religion into the sphere of science; this is where the struggle of the Church against doctrines of Galileo and Darwin belongs.

My scientific work is motivated by an irresistible longing to understand the secrets of nature not by other feelings.

Imagination is more important than knowledge. Imagination is the language of the soul. Pay attention to your imagination and you will discover all you need to be fulfilled.