Inertia
Some eras (Athenian Greece, Pre-Revolutionary America) were able to develop a fair number of people who were knowledgeable, creative, intellectually active reasoners and innovators. Are we?
In training a child to activity of thought, above all things we must beware of what I will call “inert ideas” – that is to say, ideas that are merely received into the mind without being utilised, or tested, or thrown into fresh combinations.

