How to Recognize True Knowledge

How can we be able to recognize true knowledge? Philosophically speaking, different persons have different perspectives. From rationalists’ point of view, they believe the power of pure unaided reason, which is our intuition to reason, is the way to discover the true knowledge. On the other hand, naturalists criticize naturalist’s methodology of recognizing the true knowledge.
First of all, the well-known philosopher of rationalism Descartes applies his meditation and method of extreme doubt to find true knowledge. The all over principle of Descartes s’ methodology to recognizing true knowledge is based on Cogito, Ergo sum, which states I am, therefore I exist. For instance, he assumes “ Does it now follow that I too do not exist? No: if I convinced myself of something then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that cast I too undoubtedly exist, if he is deceiving me; and let him deceive ...