Philosophy presupposes harmony - The essential argument 2022-08-22 Tuukka Pensala Perceiving, knowing or believing that the sky is blue at midday prevents one from simultaneously accepting that the color of the sky is or could be non-blue on that midday. This is because the conjunction of propositions "X" and "not-X" is a contradiction and the conjunction of "X" and "possibly-not-X" is just "X"; to meaningfully accept "not-X" or "possibly-not-X" one necessarily needs to reject "X". That is to say that the present self can not disagree with or doubt the present self; one can't within a single moment of time understand something and also accept that one may be mistaken in that understanding; the party regarded as being wrong or potentially wrong is always someone else than the present-moment self. By considering this universal assumption of present self-correctness for all humans at all future times, and by conjoining these individual assumptions, we get the proposition: Everyone is unmistaken at all future times; everyone in the future is infallible. As this total proposition consists only of understanding that is impossible to overturn in the consciousnesses of people, then any proposition that contradicts the total proposition is non-universalizable; someone at some time can't accept such a proposition. Therefore any universalizable proposition that covers the question of human fallibility, such as a philosophy, must agree with the total proposition that humans are infallible in the future. This means that a true philosophy can exist only in the case that humans indeed become infallible, which is identical to the beginning of an eternal harmonious situation. Therefore, to define a true philosophy the situation must first be made harmonious; all human accidents, conflicts and fraud must first be stopped. [2023-03-17 addition] The point can be further condensed to: Truth can be universalized only in harmony. [2024-01-07 addition] Further condensation: Human errors are bad.