The concept of philosphyphilosophy comes from the greek word "φιλοσοφία" which means KnoledgeKnowledge lover. Although the main objective of this science was getting the Truth, nowadays it deals with questions that worry humans and can´t be solved by another science.
To achieve this goal, philosophy takes advantage of the rest of the sciences, but it doesn´tdoesn't mean that is as the science used. In the same way that although physics is helped by mathematics it isn´t a formal science, philosophy is able to use logic without having to be formal. Moreover, the fact of being helped by other sciences wichwhich are not formal such psycology doesntpsychology doesn't allow it to be formal.
The easiest way ofto notice that philosophy isn´t a formal science is seeing that we cannot get an exact and accurate answer to its questions.