The main obstacle to knowing the truth is not falsehood, but the semblance of truth.
In real life, an illusion distorts reality only for a moment, but in the abstract sphere, a delusion can reign for centuries, it can put its iron yoke on entire nations, stifle humankind’s most noble impulses and, with the help of its slaves, whom it has deceived, shackle those whom it could not. It is an enemy with whom the wisest minds of all times have been waging an unequal battle, and the only things that humankind is in possession of are the things it has managed to wrestle away from it. If they say that we should search for truth even where there is no use for it because we might discover unexpected ways to apply it, then we must also add that we should search and uproot with the same zeal every delusion even where we cannot see any harm in it, because the harm of a delusion can easily show up someday in unexpected places—for every delusion conceals poison in it. If truth and knowledge have made the human being the ruler of the earth, then there are no such things as harmless delusions, much less ones that are honorable and sacred.
In consolation to those who dedicate their lives and strength to the noble and difficult battle with every kind of delusion, we can safely say that even though delusion, like owls and bats at night, will continue to do its work before the appearance of truth, owls and bats will sooner frighten and drive back the sun to where it came from than a former delusion will displace a known truth that has been fully and clearly expressed. Such is the power of truth, its victory is arduous and hard, but, on the other hand, once it has been won, it can never be taken back.
— Schopenhauer
An exposed falsehood is as important an acquisition for the good of humankind as a clearly expressed truth.
To free a human being from delusion means to give him something, not to take something away. Deliverance from falsehood is the preaching of truth, i.e. the knowledge that what is being passed off for truth is a lie. Delusion is always harmful. Sooner or later it will harm the one who accepts it as truth.
— Schopenhauer
The progress of humankind in the sphere of knowledge consists in removing the veils that cover the truth.
