One unerring mark of the love of truth is not entertaining any proposition with greater assurance than the proofs it is built upon will warrant.

Could a government dare to set out with happiness as its goal? Now that there are accepted scientific proofs it would be easy to audit the progress of national happiness annually just as we monitor money and GDP.

To be capable of steady friendship or lasting love are the two greatest proofs not only of goodness of heart but of strength of mind.

In this connection faith and experience teach us many truths by means of the short-cut of authority and by the proofs of very pleasant and agreeable feelings.

A mathematician is a person who can find analogies between theorems a better mathematician is one who can see analogies between proofs and the best mathematician can notice analogies between theories.