This way of inquiry was developed by Rene Descartes, known for his famous statement - "I think therefore I am". A religious french mathematician in the 17th century, Descartes started questioning his own reality. He was haunted by a feeling that the devil was playing a trick on him by masking reality, something like the movie The Matrix. The only way out of this was to clear himself of all his beliefs, by being skeptical at his own reasoning. He finally concluded that the only thing he can be certain of is his ability to produce thoughts, hence "I think therefore I am". Later expounded by Friedrich Nietzsche in the 19th century, this mode of reasoning led him to develop a deep understanding of morality/immorality, good/evil, true/false and rationality/irrationality. He once raised an interesting question for philosophy - "What if truth turned out to be the woman?". He pointed out that men were out there running businesses, trying to find answers of the universe, engaging in science, exploring uncharted territories of the earth, fighting each other to find the truth (keep in mind that society was highly patriarchal at his time), but what if all this was just a game. What if all these activities were just a ploy to keep the men engaged to hide the fact that the real person in charge was the wife at home. What if truth existed between the nominal acts of gossiping amongst neighboring housewives? While the men were wasting their time and energies, women had in fact found all the answers and the egos of men prevented them from seeing this. Nietzsche, often called the master of suspicion, did not strive to provide us with an answer, but rather urged us to think about what forces and powers caused us as human beings to develop distinctions between right and wrong.
In order for us to find the real answers it is not enough to question truth and facts that shape our convictions - our dogma will prevent us in this pursuit. The only way to overcome is to question the conditions and circumstances that enable us to come to a certain conclusion.