To become properly acquainted with a truth, we must first have disbelieved it, and disputed against it.

It is a principle of diplomacy that one must know something of the truth in order to lie convincingly.

If you want to assert a truth, first make sure it's not just an opinion that you desperately want to be true.

And sometimes, if you want the truth, you have to demand it.

You have to have the facts before you can pervert them.

And isn't it a bad thing to be deceived about the truth, and a good thing to know what the truth is? For I assume that by knowing the truth you mean knowing things as they really are.

To convince someone of the truth, it is not enough to state it, but rather one must find the path from error to truth.

The only way to progress is by stumbling, falling, and getting up, time and again. Error will always be there because the best decisions are always, to some extent, bound up in error. In the great challenge of separating truth from lies—a goal, perhaps the most human of all goals, that is perfectly possible to achieve—it is essential to bear in mind that in this task there can never be definitive achievements that cannot be challenged later, and no knowledge that cannot be revised. In the great forest of misperceptions and deceptions, mistakes and mirages, through which we roam, the only way that truth can clear a path is by rational and systematic criticism of what is—or passes for—knowledge. Without this privileged expression of freedom, the right to criticize, we are condemned to oppression, brutality, and also obscurantism.

Knowledge, like religion, must be "experienced" in order to be known.

He argued that when the truth is not known, we desire to know it, but once we do know it, there are not a few cases in which we repent our knowing and envy that earlier time when we lived blissfully ignorant.

One must at least know what the lies are.

If a person is to get the meaning of life he must learn to like the facts about himself — ugly as they may seem to his sentimental vanity — before he can learn the truth behind the facts. And the truth is never ugly.

to know truth one must get rid of knowledge,

To know, you just have to know. To believe, you have to make others believe.