Good problems and mushrooms of certain kinds have something in common; they grow in clusters.
How to Solve It: A New Aspect of Mathematical MethodWith the truth, all given facts harmonize; but with what is false, the truth soon hits a wrong note.
The Nicomachean EthicsThe pleasures arising from thinking and learning will make us think and learn all the more. 1153a 23
The Nicomachean Ethics