Cultural Knowledge – Preparation for Teaching an Additional Subject

They never open their mouths without subtracting from the sum of human knowledge.

Manners must adorn knowledge, and smooth its way through the world. Like a great rough diamond, it may do very well in a closet by way of curiosity, and also for its intrinsic value; but it will never be worn, nor shine, if it is not polished.

Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.