"Are we alone?" A Princeton University Coursera class allows one to speculate scientifically about that question, HERE. There is also a class from UPenn on "Plato & His Predecessors" HERE that, while unrelated, looks interesting.
I can't remember if these are free or not (many times they are) but usually you can find some gems. I finished a Coursera course in "Philosophy of Mathematics" and it was very helpful for my own research. It was of course very interesting and fun to accomplish.