This was a question on Quora, and this is my answer, which, hopefully, explains the shameless self-referencing to this blog.
Who says they do? I think this is one of those questions that should be reworded: what distinguishes a philosopher’s thinking from most other people’s? I’m not sure there is a definitive answer to this, because, like other individuals, every philosopher is unique. The major difference is that they spend more time writing down what they’re thinking than most people, and I’m a case in point.
Not that I’m a proper philosopher, in that it’s not my profession – I’m an amateur, a dilettante. I wrote a little aphorism at the head of my blog that might provide a clue.
Philosophy, at its best, challenges our long held views, such that we examine them more deeply than we might otherwise consider.
Philosophy, going back to Socrates, is all about argument. Basically, Socrates challenged the dogma of his day and it ultimately cost him his life. I write a philosophy blog and it’s full of arguments, not that I believe I can convince everyone to agree with my point of view. But basically, I hope to make people think outside their comfort zone, and that’s the best I can do.
Socrates is my role model, because he was the first (that we know of) who challenged the perceived wisdom provided by figures of authority. In Western traditions tracing the more than 2 millennia since Socrates, figures of authority were associated with the Church, in all its manifestations, where challenging them could result in death or torture or both.
That’s no longer the case - well, not quite true - try following that path if you’re a woman in Saudi Arabia or Iran. But, for most of us, living in a Western society, one can challenge anything at all, including whether the Earth is a sphere.
Back to the question, I don’t think it can be answered, even in the transcribed form that I substituted. Personally, I think philosophy in the modern world requires analysis and a healthy dose of humility. The one thing I’ve learned from reading and listening to many people much smarter than me is that the knowledge we actually know is but a blip and it always will be. Nowhere is this more evident than in mathematics. There are infinitely more incomputable numbers than computable numbers. So, if our knowledge of maths is just the tip of a universe-sized iceberg, what does that say about anything else we can possibly know.
Perhaps what separates a philosopher’s thinking from most other people’s is that they are acutely aware of how little we know. Come to think of it, Socrates famously made the same point.