What makes our opponents useful is that they allow us to believe that without them we would be able to realize our goals..

The biologist passes. The frog stays the same..

It may offend us to hear our own thoughts expressed by others: we are not sure enough of their souls..

We are not naïve enough to ask for pure men; we ask merely for men whose impurity does not conflict with the obligations of their job..

The ideal, without doubt, varies, but its enemies, alas, are always the same..

It takes a very deep-rooted opinion to survive unexpressed..

Kill one man and you're a murderer, kill a million and you're a conqueror..

Le biologiste passe, la grenouille reste. The biologist passes, the frog remains..

We bestow on others praise in which we do not believe, on condition that in return they bestow upon us praise in which we do..

The least one can say of power is that a vocation for it is suspicious..

We must watch over our modesty in the presence of those who cannot understand its grounds..

If a given scientist had not made a given discovery, someone else would have done so a little later. Johann Mendel dies unknown after having discover….

One must credit an hypothesis with all that has had to be discovered in order to demolish it..

Renown? I've already got more of it than those I respect, and will never have as much as those for whom I feel contempt..

To live is often to struggle toward goals one has no desire to reach..

Take heed of critics even when they are not fair; resist them even when they are..

Science had better not free the minds of men too much, before it has tamed their instincts..

Nothing leads the scientist so astray as a premature truth..

My pessimism extends to the point of even suspecting the sincerity of other pessimists..

In politics, yesterday's lie is attacked only to flatter today's..

Kill one man, and you are a murderer. Kill millions of men, and you are a conqueror. Kill them all, and you are a god..