I think we can only make assumptions about who the real founder of philosophy was. The truth is, there were a lot of philosophers even before Socrates who happened to be the father of western philosophy was born. Majority of these philosophers didn't have written records of their own, and as a result, people don't have much information about them. These people actually started various philosophical methods that are being used today. Examples of those philosophical methods are; rational argument, questioning, critical thinking, etc.
Even Socrates who happened to be the father of western philosophy didn't have most of his records written. However, Plato, a student of Socrates, can still be regarded as the founder of philosophy. The reason is that he was the first to have his own ideas, thoughts are written down. Although, most of the things that Plato wrote were things he learned from his master. Also, most of his philosophies were gotten through dialogues