If human beings could be propagated by cutting, like apple trees, aristocracy would be biologically sound.

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

An attempt to study the evolution of living organisms without reference to cytology would be as futile as an account of stellar evolution which ignored spectroscopy.

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

Quantitative work shows clearly that natural selection is a reality, and that, among other things, it selects Mendelian genes, which are known to be distributed at random through wild populations, and to follow the laws of chance in their distribution to offspring. In other words, they are an agency producing variation of the kind which Darwin postulated as the raw material on which selection acts.

The conclusion forced upon me in the course of a life devoted to natural science is that the universe as it is assumed to be in physical science is only an idealized world, while the real universe is the spiritual universe in which spiritual values count for everything.

I do not believe in the commercial possibility of induced radioactivity.