Since the great foundation of fear is pain, the way to harden and fortify children against fear and danger is to accustom them to suffer pain.
John LockeAs it is in the body, so it is in the mind; practice makes it what it is, and most even of those excellencies, what are looked on as natural endowments, will be found, when examined into more narrowly, to be the product of exercise, and to be raised to that pitch, only by repeated actions.
John LockeBrutes abstract not. -- If it may be doubted, whether beasts compound and enlarge their ideas, that way, to any degree; this, I think, I may be positive in, that the power of abstracting is not at all in them; and that the having of general ideas is that which puts a perfect distinction betwixt man and brutes, and is an excellency which the faculties of brutes do by no means attain to.
John Locke