My mind has changed during the last twenty or thirty years... Now for many years I cannot endure to read a line of poetry… I have also almost lost any taste for pictures or music… My mind seems to have become a kind of machine for grinding general laws out of large collections of facts...

If I had to live my life again I would have made a rule to read some poetry and listen to some music at least once every week… The loss of these tastes is a loss of happiness, and may possibly be injurious to