The “stream” we call science always flows forward; sometimes reactionary beavers block its flow, but the stream is never defeated by this; it accumulates, gathers strength; its waters get over the barrage and continue on their course. The advancement of science is the advancement of God, for science is nothing but human intelligence, and human intelligence is the most valuable treasure God has bequeathed us.
There are pauses amidst study, and even pauses of seeming idleness, in which a process goes on which may be likened to the digestion of food. In those seasons of repose, the powers are gathering their strength for new efforts; as land which lies fallow recovers itself for tillage.
To be seventy years old is like climbing the Alps. You reach a snow-crowned summit, and see behind you the deep valley stretching miles and miles away, and before you other summits higher and whiter, which you may have strength to climb, or may not. Then you sit down and meditate and wonder which it will be.
To dream anything that you want to dream. That's the beauty of the human mind. To do anything that you want to do. That is the strength of the human will. To trust yourself to test your limits. That is the courage to succeed.