An ounce of algebra is worth a ton of verbal argument.

A time will however come (as I believe) when physiology will invade and destroy mathematical physics, as the latter has destroyed geometry.

While I do not suggest that humanity will ever be able to dispense with its martyrs, I cannot avoid the suspicion that with a little more thought and a little less belief their number may be substantially reduced.

The idea of protoplasm, which was really a name for our ignorance, [is] only a little less misleading than the expression "Vital force".

I have never yet met a healthy person who worried very much about his health, or a really good person who worried much about his own soul.

It was a reaction from the old idea of "protoplasm", a name which was a mere repository of ignorance.

The world shall perish not for lack of wonders, but for lack of wonder