The theory of relativity worked out by Mr. Einstein, which is in the domain of natural science, I believe can also be applied to the political field. Both democracy and human rights are relative concepts - and not absolute and general.

On the basis of Lorentz's theory, if we limit ourselves to a single spectral line, it suffices to assume that each atom (or molecule) contains a single moving electron.

I should point out, however, that at first some difficulty was experienced in observing the phenomena predicted by the theory, owing to the extreme smallness of the variations in the period of oscillation.

If you want to know the taste of a pear, you must change the pear by eating it yourself. If you want to know the theory and methods of revolution, you must take part in revolution. All genuine knowledge originates in direct experience.

A political theory seeks to find from history the limits of the politically possible.

To an intellectual who is adrift in politics, a theory is an aim; to a true politician his theory is a boundary.

In theory, I'd like to work in a group. But the group I'd like to work in, all the musicians in them are long since dead.

I am relying on the theory that playing golf is just like riding a bike and that I haven't forgotten how.

My theory of evolution is that Darwin was adopted.

Thought and theory must precede all salutary action; yet action is nobler in itself than either thought or theory.

Frankly, these days, without a theory to go with it, I can't see a painting.

Philosophy is not a theory but an activity.

If I take the theory as we have it now, literally, I would conclude that extra dimensions really exist. They're part of nature. We don't really know how big they are yet, but we hope to explore that in various ways.

I wouldn't have thought that a wrong theory should lead us to understand better the ordinary quantum field theories or to have new insights about the quantum states of black holes.

Even before string theory, especially as physics developed in the 20th century, it turned out that the equations that really work in describing nature with the most generality and the greatest simplicity are very elegant and subtle.