In politics:
He who desires to attempts to reform the government of a state, and wishes to have it accepted, must at least retain the semblance of the old forms; so that it may seem to the people that there has been no change in the institutions, even though in fact they are entirely different from the old ones. For the great majority of mankind are satisfied with appearances, as though they were realities.
Niccolo Machiavelli
In science:
A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.
Max Plank
Both from the book The 48 Laws of Power by Robert Greene.