It is better to enlighten men’s minds than to teach them to be obstinate in their prejudices. - Pierre-Joseph Proudhon

For me, the response is simple. All ideas are false, that is to say contradictory and irrational, if one takes them in an exclusive and absolute sense, or if one allows oneself to be carried away by that sense; all are true, susceptible to realization and use, if one takes them together with others, or in evolution.

What, I ask, has the fixed and solid nature of the earth to do with the right of appropriation?
(...)
But the creator of the land does not sell it: he gives it; and, in giving it, he is no respecter of persons. Why, then, are some of his children regarded as legitimate, while others are treated as bastards? If the equality of shares was an original right, why is the inequality of conditions a posthumous right?

Justice is the central star which governs societies, the pole around which the political world revolves, the principle and the regulator of all transactions. Nothing takes place between men save in the name of right; nothing without the invocation of justice. Justice is not the work of the law: on the contrary, the law is only a declaration and application of justice in all circumstances where men are liable to come in contact. If, then, the idea that we form of justice and right were ill-defined, if it were imperfect or even false, it is clear that all our legislative applications would be wrong, our institutions vicious, our politics erroneous: consequently there would be disorder and social chaos.
This hypothesis of the perversion of justice in our minds, and, as a necessary result, in our acts, becomes a demonstrated fact when it is shown that the opinions of men have not borne a constant relation to the notion of justice and its applications; that at different periods they have undergone modifications: in a word, that there has been progress in ideas. Now, that is what history proves by the most overwhelming testimony.