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

The advance of scientific knowledge does not seem to make either our universe or our inner life in it any less mysterious.

The Creator would appear as endowed with a passion for stars, on the one hand, and for beetles on the other, for the simple reason that there are nearly 300,000 species of beetle known, and perhaps more, as compared with somewhat less than 9,000 species of birds and a little over 10,000 species of mammals.

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

Now, if the cooperation of some thousands of millions of cells in our brain can produce our consciousness, a true singularity, the idea becomes vastly more plausible that the cooperation of humanity, or some sections of it, may determine what Comte calls a Great Being.

Every Christian church has tried to impose a code of morals of some kind for which it has claimed divine sanction. As these codes have always been opposed to those of the gospels a loophole has been left for moral progress such as hardly exists in other religions.