Moving into the D's, we have a trio of the Darwin family expounding on science.
"There is a grandeur in this view of life." - Charles Darwin, English naturalist and scientist, 1809-82
"A fool... is a man who never tried an experiment in his life." - Erasmus Darwin, English physician and grandfather of Charles Darwin, 1731-1802
"In science the credit goes to the man who convinces the world, not to the man to whom the idea first occurs." - Francis Darwin, English botanist and son of Charles Darwin, 1848-1925
With a nod to Olympic patriotism, here is a Canadian quotation to change things up a bit:
"I see Canada as a country torn between a very northern, rather extraordinary, mystical spirit which it fears and its desire to present itself to the world as a Scotch banker." - Robertson Davies, Canadian novelist, 1913-95