From the definition from Wikipedia:
Philosophy is the study of general and fundamental problems, such as those connected with reality, existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational argument.
As said in definition it doesn't address problems by its "critical, generally systematic approach and its reliance on rational argument" etc. So my question is: how does philosophy study the fundamental problems mentioned above? Does it use mathematics to study them? For example if it wants to study what mind is. Where would the examples come from? Based on which truth and facts would philosophy make an argument which would be true?