I believe there exists, & I feel within me, an instinct for the truth, or knowledge or discovery, of something of the same nature as the instinct of virtue, & that our having such an instinct is reason enough for scientific researches without any practical results ever ensuing from them.

Here the ways of men part: if you wish to strive for peace of soul and pleasure, then believe; if you wish to be a devotee of truth, then inquire.

We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.

People still believe what they read is necessarily the truth.

Among other common lies, we have the silent lie - the deception which one conveys by simply keeping still and concealing the truth. Many obstinate truth-mongers indulge in this dissipation, imagining that if they speak no lie, they lie not at all.

My way of joking is to tell the truth. It's the funniest joke in the world.