Winter is the time for study, you know, and the colder it is the more studious we are.

The virtue of making two blades of grass grow where only one grew before does not begin to be superhuman.

We are all of us Apollos serving some Admetus.

I am sorry to think that you do not get a man's most effective criticism until you provoke him. Severe truth is expressed with some bitterness.

It is impossible to say all that we think, even to our truest Friend. We may bid him farewell forever sooner than complain, for our complaint is too well grounded to be uttered.

You can hardly convince a man of an error in a lifetime, but must content yourself with the reflection that the progress of science is slow. If he is not convinced, his grandchildren may be.

What can be expressed in words can be expressed in life.