The dogma of the infallibility of the Bible is no more self-evident than is that of the infallibility of the popes.

In truth, the laboratory is the forecourt of the temple of philosophy, and whoso has not offered sacrifices and undergone purification there has little chance of admission into the sanctuary.

The method of scientific investigation is nothing but the expression of the necessary mode of working of the human mind.

Proclaim human equality as loudly as you like, Witless will serve his brother.

Thoughtfulness for others, generosity, modesty, and self-respect are the qualities which make a real gentleman or lady.

I have endeavoured to show that no absolute structural line of demarcation, wider than that between the animals which immediately succeed us in the scale, can be drawn between the animal world and ourselves; and I may add the expression of my belief that the attempt to draw a physical distinction is equally futile, and that even the highest faculties of feeling and of intellect begin to germinate in lower forms of life.

A well-worn adage advises those who set out upon a great enterprise to count the cost, yet some of the greatest enterprises have succeeded because the people who undertook them did not count the cost.