Don't do anything that goes against your conscience, even if your country says so.
If you took half of something and continued to take half of that half and so on, you would never reach an end.
If we have the courage to decide ourselves for peace we will have peace.
If you've never failed, you've never tried anything new.
If I had 20 days to solve a problem, I would take 19 days to define it
If I can't picture it, I can't understand it.
I wouldn't want to live if I did not have my work. In any case, it's good that I'm already old and personally don't have to count on a prolonged future.
If there is no price to be paid, it is also not of value.
If I am right the Germans will say I was a German, and the French will say I was a Jew; If I am wrong the Germans will say I was a Jew and the French will say I was a German.
If one studies too zealously, one easily loses his pants.
Even if you have to go through hell - go without hesitation.
One can only continue to expect to be read if one omits everything that is unimportant.
If I had it [life] to do all over again, I'd have been a plumber.
If I were wrong, wouldn't one be enough?
Philosophy is empty if it isn't based on science. Science discovers, philosophy interprets.
If I had known they were going to do this, I would have become a shoemaker.
I have reached an age where if someone tells me to wear socks, I dont have to
If tomorrow were never to come, it would not be worth living today.
If you have never failed, you have never tried anything new.
If you do the same thing over and over again you cannot ever expect a different outcome.
The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.
If you can't explain something simply, you don't know enough about it.