The truth of any knowledge and object can be proved or questioned. The Kantian antinomy, which says that even two opposite hypotheses can be logically substantiated, puts true knowledge in the rank of a mythical animal.
Such a beast, perhaps, does not exist at all, and Karamazov’s “nothing is truth, everything is permitted” should become the highest postulate of human life. But first things first.
Philosophical relativism, and later - solipsism, pointed out to the world that true knowledge is not always such. The problem of what in philosophy can be considered genuine and what is false has been raised for a very long time. The most famous antique example of the struggle for the truth of judgments is the argument of Socrates with the Sophists and the famous saying of the philosopher: "I know that I know nothing." Sophists, by the way, were among the first to question almost everything.
The times of theology pacified a little the ardor of philosophers, giving a "only true" and righteous view of life and the creation of the world by God. But Giordano Bruno and Nikolai Kuzansky, thanks to their scientific discoveries, have empirically proved that the Sun does not revolve around the Earth, and the planet itself is not the center of the universe. The discovery of philosophers and scientists of the 15th century made disputes about what true knowledge means again, since the planet, as it turned out, was rushing through uncharted and frightening outer space.
At that time, new philosophical schools began to appear and science developed.
So, true is knowledge, according to Aristotle, which is fully true. This approach is easy enough to criticize, because it does not take into account both deliberate misconceptions and craziness. R. Descartes, however, believed that true knowledge differs from false knowledge in that it has clarity. Another philosopher D. Berkeley believed that truth is what the majority agrees with. But be that as it may, the most important criterion of truth is its objectivity, that is, independence from man and his consciousness.
It cannot be said that humanity, complicating technology, has come so close to denying any error that true knowledge is already at arm's length.
Modern technologies, computers, and the Internet are in the hands of uneducated and unprepared societies, which has led to information intoxication and gluttony. Nowadays, information oozes from all the slots, and only the real Moses from programming and social sciences can curb this stream. This picture was rather vividly described already 50 years ago, namely in the book 1984 written by J. Orwell and in the novel Oh Brave New World by Aldous Huxley.
True knowledge can be worldly, scientific or artistic, as well as moral. In general, there are as many truths as there are in the world of professions. For example, the problem of hunger in Africa is a problem for a scientist requiring a systematic approach, and for a believer it is a punishment for sins. That is why so many unremitting disputes go around many phenomena, and, unfortunately, high-speed technologies, science and globalization have not yet been able to bring mankind even to the solution of the simplest moral issues.
