I used to go away for weeks in a state of confusion.

Those who condemn the supreme certainty of mathematics feed on confusion, and can never silence the contradictions of the sophistical sciences which lead to eternal quackery.

But hereditary diseases and some other facts make me believe that the rule has a wider extension, and that, when there is no apparent reason why a peculiarity should appear at any particular age, yet it does tend to appear in the offspring at the same period at which it first appeared in the parent. I believe this rule to be of the highest importance in explaining the laws of embryology.

We desire to see the return of a liberal age where Parliaments will guard freedom, where science will open the banqueting halls to the millions, and where what Bismarck once called "practical Christianity" will mitigate suffering and misfortunes.

To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, and leave the rest for others that come after you, than to explain all things by conjecture without making sure of anything.

Reality is merely an illusion, albeit a very persistent one.