For belligerent purposes, the 14th century, like the 20th, commanded a technology more sophisticated than the mental and moral capacity that guided its use.

What his imagination is to the poet, facts are to the historian. His exercise of judgment comes in their selection, his art in their arrangement.

For me, the card catalog has been a companion all my working life. To leave it is like leaving the house one was brought up in.

The fact of being reported increases the apparent extent of a deplorable development by a factor of ten.

Learning from experience is a faculty almost never practiced

The unrecorded past is none other than our old friend, the tree in the primeval forest which fell without being heard

One must stop conducting research before one has finished. Otherwise, one will never stop and never finish.