Ideas need not stand continuous duty, like sentries; you can abandon one without another fresh and ready to take its place.
Operations of thought are like cavalry charges in a battle — they are strictly limited in number, require fresh horses, and must only be made at decisive moments.
If only thought were conserved like matter, if lost thoughts were transmuted instead of vanishing forever.
When a philosopher says that you have denied the metaphysical nature of something he means that you have explained it.
Less likely that it is complicated than that you are simple.
Knowledge is to have a hammer; wisdom is to recognize what’s not a nail.
Most buts should be ands.
Inspiration only dramatizes thought for those who cannot think. Physical laws do not come from falling apples, or poems from opium dreams.
What makes a fool? The gap between what he knows and what he thinks he knows — in short, opinions.
Any idiot can have a good idea; it takes a genius to recognize one.
List, and the world lists with you; abstract, and you abstract alone.