Whoever marries the spirit of this age will find himself a widower in the next.

The church is only a secular institution in which the half-educated speak to the half-converted.

Don't break the silence unless you can improve on it.

Faith begins as an experiment, and ends as an experience.

The greatest obstacle to progress is not man's inherited pugnacity, but his incorrigible tendency to parasitism.

Over-population is a phenomenon connected with the survival of the unfit, and it is a mechanism which has created conditions favourable to the survival of the unfit and the elimination of the fit.

In praising science, it does not follow that we must adopt the very poor philosophies which scientific men have constructed. In philosophy they have much more to learn than to teach.