The application of algebra to geometry ... has immortalized the name of Descartes, and constitutes the greatest single step ever made in the progress of the exact sciences.

The real advantage which truth has, consists in this, that when an opinion is true, it may be extinguished once, twice, or many times, but in the course of ages there will generally be found persons to rediscover it

The duty of man is the same in respect to his own nature as in respect to the nature of all other things, namely not to follow it but to amend it.

... what is really inspiriting and ennobling in the doctrine of freewill, is the conviction that we have real power over the formation of our own character; that our will, by influencing some of our circumstances, can modify our future habits or capabilities of willing.

As long as justice and injustice have not terminated their ever renewing fight for ascendancy in the affairs of mankind, human beings must be willing, when need is, to do battle for the one against the other.

What is contrary to women's nature to do, they never will be made to do by simply giving their nature free play.

War is an ugly thing, but not the ugliest of things: the decayed and degraded state of moral and patriotic feeling which thinks nothing worth a war, is worse. A war to protect other human beings against tyrannical injustice; a war to give victory to their own ideas of right and good, and which is their own war, carried on for an honest purpose by their own free choice - is often the means of their regeneration.