Any idea can be brought into the classroom if the point is to inquire into its structure, history, influence and so forth. But no idea belongs in the classroom if the point of introducing it is to recruit your students for the political agenda it may be thought to imply.
“Remember that a painting - before it is a battle horse, a nude model, or some anecdote - is essentially a flat surface covered with colours assembled in a certain order.”
“A friend who is far away is sometimes much nearer than one who is at hand. Is not the mountain far more awe-inspiring and more clearly visible to one passing through the valley than to those who inhabit the mountain?”