People tell you that wishful thinking is bad. Do not believe it, this is just one of those generally accepted errors. - George Pólya

To write and speak correctly is certainly necessary; but it is not sufficient. A derivation correctly presented in the book or on the blackboard may be inaccessible and uninstructive, if the purpose of the successive steps is incomprehensible, if the reader or listener cannot understand how it was humanly possible to find such an argument....

Analogy pervades all our thinking, our everyday speech and our trivial conclusions as well as artistic ways of expression and the highest scientific achievements.

[M]athematicians and physicists think alike; they are led, and sometimes misled, by the same patterns of .