Instrumental or mechanical science is the noblest and above all others, the most useful.

Wisdom is the daughter of experience

As every divided kingdom falls, so every mind divided between many studies confounds and saps itself.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

It reflects no great honor on a painter to be able to execute only one thing well -- such as a head, an academy figure, or draperies, animals, landscapes, or the like -- in other words, confining himself to some particular object of study. This is so because there is scarcely a person so devoid of genius as to fail of success if he applies himself earnestly to one branch of study and practices it continually.

Threats alone, are the weapons of the threatened man.

Being willing is not enough. We must do.