Even in the dark times between experimental breakthroughs, there always continues a steady evolution of theoretical ideas, leading almost imperceptibly to changes in previous beliefs.

It was one time when people thought the value of the fine structure constant was important. Now of course it's still important, of course, as a practical matter,but we now know that the value it has is a function, that in any fundamental theory you derive the fine structure constant as a function of all sorts of mass ratios and so on and it's not really that fundamental.

I now want to tell three stories about advances in twentieth-century physics. A curious fact emerges in these tales: time and again physicists have been guided by their sense of beauty not only in developing new theories but even in judging the validity of physical theories once they are developed. Simplicity is part of what I mean by beauty, but it is a simplicity of ideas, not simplicity of a mechanical sort that can be measured by counting equations or symbols.

You know, our fundamentalist friends dislike the teaching of evolution in schools because of the effect they feel it has on our view of our own special importance, while liberals insist that scientific and spiritual matters can be kept in separate compartments. On this point, I tend to agree with the fundamentalists, though I come to opposite conclusions about teaching evolution because I am convinced it's true.

All logical arguments can be defeated by the simple refusal to reason logically

If there is no point in the universe that we discover by the methods of science, there is a point that we can give the universe by the way we live, by loving each other, by discovering things about nature, by creating works of art. And that — in a way, although we are not the stars in a cosmic drama, if the only drama we're starring in is one that we are making up as we go along, it is not entirely ignoble that faced with this unloving, impersonal universe we make a little island of warmth and love and science and art for ourselves. That's not an entirely despicable role for us to play.

The effort to understand the universe is one of the very few things that lifts human life a little above the level of farce, and gives it some of the grace of tragedy.