According to Carl Popper, truth is not something that is discovered. Therefore the truth is always temporary, it remains in force only until it is rejected. In contemplating these words of Carl Popper we come to the conclusion that he is right. This is the very reality around us, life itself: it is looking, it proves, it lives with one truth, until it is later determined that this it is not the truth itself. And this is quite natural, because everything evolves and progresses. In the beginning, truth exists in the form of a hypothesis or theory in solving a question. It follows a long process of laboratory experiments, mathematical calculations, scientific evidence until the truth is obtained as a knowledge of a certain realm of reality.
This process of proofing may be short, but can be very lengthy in time.
It can even change everything while this process of experiments and proofs and finally arrives at another truth, not from the one that went hypothetically. Then a new theory emerges. The changes around us affect life and cause consequences. Then the new truth comes out and all attempts and evidence begin again with a new force of spirit and new scientific quests. The truth is uncertain because science is also vulnerable as a work of people. There are truths that can not be dismissed and replaced. For example, the earth is round. Human progress continually proves the existence of truth in many areas: Science, technology, politics. In this endless process, the mistakes are not ruled out. By rejecting mistakes, it goes forward to progress. According to Popper, the construction of the truth is "step by step". It makes criticism - that is, the exercise of freedom as the basis of progress. Without criticism, no progress in science or improvement of public life is possible. There are some truths we live with for years without the right to critique, and the time comes when they break down and begin a long period of proof and building a new truth that does not know whether it will eventually be proven or replaced by a new one. For example, the Perestroika process destroyed many of them, questioned a whole theory of Marxism - Leninism.
There are other truths that are not the proof of proof, they simply have to be accepted as described - for example, the religious writings of fundamentalist Islamic societies (present-day Iran) All truths go through the process of experiencing and correcting mistakes. It is not known whether after years, in time, progress will not prove many new truths that will deny a number of old, will prove and perhaps change people's perception of the world, science, technique. It should never be forgotten that there is no final success that can not be challenged in the end, nor knowledge that is not subject to revision. Either way, no other thinker Popper has turned freedom into a condition that is human, because it guarantees civilized forms of existence and cultural creation. Popper 's theory of cognition is the best philosophical justification of ethical value that most accurately characterizes a democratic culture: tolerance.