There is no hope for any speculation that does not look absurd at first glance.

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.

How wonderful that we have met with a paradox. Now we have some hope of making progress.

No paradox, no progress.

Of course I don't believe in it [pointing to horseshoe on his office wall]. But I understand that it brings you luck whether you believe in it or not.

There are two sorts of truth: trivialities, where opposites are clearly absurd, and profound truths, recognised by the fact that the opposite is also a profound truth

Anyone who can contemplate quantum mechanics without getting dizzy hasn't understood it.