The logic now in use serves rather to fix and give stability to the errors which have their foundation in commonly received notions than to help the search for truth. So it does more harm than good.

Logic is a way of going wrong systematically.

Nothing is more damaging to a new truth than an old error.

Some persons fancy that bias and counter-bias are favorable to the extraction of truth–that hot and partisan debate is the way to investigate. This is the theory of our atrocious legal procedure. But Logic puts its heel upon this suggestion. It irrefragably demonstrates that knowledge can only be furthered by the real desire for it, and that the methods of obstinacy, of authority and every mode of trying to reach a foregone conclusion, are absolutely of no value. These things are proved. The reader is at liberty to think so or not as long as the proof is not set forth, or as long as he refrains from examining it. Just so, he can preserve, if he likes, his freedom of opinion in regard to the propositions of geometry; only, in that case, if he takes a fancy to read Euclid, he will do well to skip whatever he finds with A, B, C, etc., for, if he reads attentively that disagreeable matter, the freedom of his opinion about geometry may unhappily be lost forever.

I then thought, and am still of the same opinion, that error, and not truth of any kind, is dangerous; that ill conclusions can only flow from false propositions; and that, to know whether any proposition be true or false, it is a preposterous method to examine it by its apparent consequences.

You can only find truth with logic if you have already found truth without it.

"La vérité ne fait pas tant de bien dans le monde que ses apparences y font de mal.

"Truth does less good in the world than the appearance of truth does evil.

Logic is immaturity weaving its nets of gossamer wherewith it aims to catch the behemoth of knowledge. When Logic comes of age it strangles itself in its nets and then becomes transmuted into Faith, which is the deeper knowledge. Logic is a crutch for the cripple; but a burden for the swift of foot; and a greater burden still for the winged.

Truth gains more even by the errors of one who, with due study and preparation, thinks for himself, than by the true opinions of those who only hold them because they do not suffer themselves to think…

Logic is a poor model of cause and effect.

It is more reasonable to remove error from truth, than to venerate error because it is mix'd with truth.

The need of reason is not inspired by the quest for truth but by the quest for meaning. And truth and meaning are not the same. The basic fallacy, taking precedence over all specific metaphysical fallacies, is to interpret meaning on the model of truth.

Logic is a feeble reed, friend. "Logic" proved that airplanes can't fly and that H-bombs won't work and that stones don't fall out of the sky. Logic is a way of saying that anything which didn't happen yesterday won't happen tomorrow.

Knowledge rests not upon truth alone, but upon error also.