We never know what we are talking about.

True ignorance is not the absence of knowledge, but the refusal to acquire it.

The growth of knowledge depends entirely upon disagreement.

In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality.

The question is not how to get good people to rule; THE QUESTION IS: HOW TO STOP THE POWERFUL from doing as much damage as they can to us.

If you can't say it simply and clearly, keep quiet, and keep working on it till you can.

The best thing that can happen to a human being us to find a problem, to fall in love with that problem, and to live trying to solve that problem, unless another problem even more lovable appears.

Ignorance is not a simple lack of knowledge but an active aversion to knowledge, the refusal to know, issuing from cowardice, pride, or laziness of mind.

A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice.

I may be wrong and you may be right, and by an effort, we may get nearer to the truth

The attempt to make heaven on earth invariably produces hell.

Words have great cumulative power, but in the 21st century, a single image is much stronger. An image suggests the unvarnished truth. That is its power and its fiction.

I reserve the right, as president of the United States to meet with anybody at a time and place of my choosing if I think it's going to keep America safe.

We are against any WMD, any weapons of mass destruction, whether chemical or nuclear.

I want to be the most durable person on the planet.

I wish I could tell you that the Children's Television Workshop and Sesame Street were thanks to my genius, but it really was a lucky break.

We 've lost something else: the relationship between men and women.

Running became boring because it's so predictable. I got to a point where I knew what my competition could do.

The simple fact is that what you see on the screen is pretty much real.

‎Imprinting on someone is like... Like when you see her... Everything changes. All of a sudden, its not gravity holding you to the planet. It's her... Nothing else matters.