Be gentle to all and stern with yourself.
Without hard work, nothing grows but weeds.
The wise does at once what the fool does at last.
Either you run the day or the day runs you.
Go for it now. The future is promised to no one.
Begin to be now what you will be hereafter.
I can, therefore I am.
If you're going through hell, keep going.
Leap, and the net will appear.
What you do today can improve all your tomorrows.
Triumphant science and technology are only at the threshold of man's command over sources of energy so stupendous that, if used for military purposes, they can wipe out our entire civilization.