No induction, however broad its basis, can confer certainty—in the strict sense of the word. The experience of the whole human race through innumerable years has shown that stones unsupported fall to the ground, but that does not make it certain that any day next week unsupported stones will not move the other way. All that it does justify is the very strong expectation, which hitherto has been invariably verified, that they will do just the contrary.
Only one absolute certainty is possible to man—namely, that at any given moment the feeling which he has exists.
All other so-called certainties are beliefs of greater or less intensity.
Of moral purpose I see no trace in Nature. That is an article of exclusively human manufacture—and very much to our credit.
There is nothing of permanent value (putting aside a few human affections), nothing that satisfies quiet reflection—except the sense of having worked according to one's capacity and light, to make things clear and get rid of cant and shams of all sorts. That was the lesson I learned from Carlyle's books when I was a boy, and it has stuck by me all my life.
You may make more of failing to get money, and of succeeding in getting abuse—until such time in your life (if you are teachable) you have ceased to care much about either.
The doctrine of the conservation of energy tells neither one way nor the other [on the doctrine of immortality]. Energy is the cause of movement of body, i.e. things having mass. States of consciousness have no mass, even if they can be conceded to be movable. Therefore even if they are caused by molecular movements, they would not in any way affect the store of energy.