Teach a child what is wise, that is morality. Teach him what is wise and beautiful, that is religion!

[Scientists] have learned to respect nothing but evidence, and to believe that their highest duty lies in submitting to it however it may jar against their inclinations.

'Infidel' is a term of reproach, which Christians and Mohammedans, in their modesty, agree to apply to those who differ from them.

There is no alleviation for the sufferings of mankind except veracity of thought and of action, and the resolute facing of the world as it is when the garment of make-believe by which pious hands have hidden its uglier features is stripped off.

Missionaries, whether of philosophy or religion, rarely make rapid way, unless their preachings fall in with the prepossessions ofthe multitude of shallow thinkers, or can be made to serve as a stalking-horse for the promotion of the practical aims of the still larger multitude, who do not profess to think much, but are quite certain they want a great deal.

Unfortunately, it is much easier to shut one's eyes to good than to evil. Pain and sorrow knock at our doors more loudly than pleasure and happiness; and the prints of their heavy footsteps are less easily effaced.

If there is anything in the world which I do firmly believe in, it is the universal validity of the law of causation.