While doing research on human immortality, it’s not too surprising that I came across the Wikipedia article on the Philosopher’s Stone. Granting immortality was actually not the primary function of the Stone. Rather, it was said to be able to transmute base metals into gold. Yes, the alchemists were just as interested in gold as Glenn Beck is today.
Searching for this magical stone was known as the Great Work of alchemy. Somehow, it also came to be associated with elixir that would restore a person’s youth and vitality, possibly because this constituted perfecting the human body in the same way that gold was regarded as metal perfection.
I first remember seeing references to the Philosopher’s Stone in Spells of Enchantment, a collection of fairy tales compiled by Jack Zipes. A few of them mentioned the Stone, concentrating on its ability to produce gold. This was before the release of Harry Potter and the Philosopher’s Stone, the title of which was changed for American audiences, presumably because the publishers were afraid potential readers would otherwise think it was about philosophers instead of wizards.
Mind you, I’m not sure that many British children had heard of the Philosopher’s Stone either, but apparently they were supposed to be able to find out what one was by actually reading the book. Besides, I’m sure at least a few readers would have heard of a Philosopher’s Stone, while exactly zero of them would know about a “Sorcerer’s Stone,” because, well, it wasn’t anything. For that matter, I don’t think anyone in the series was ever called a sorcerer, so doesn’t using the word in this one context just make things more confusing? Besides, nobody seemed to mind Scrooge McDuck searching for a properly named Philosopher’s Stone back in the forties. (I need to read that story, by the way.)
That said, I really couldn’t tell you what the Stone has to do with philosophers.
The Wikipedia article proposes that the Stone was based on the Cintamani of Hindu mythology, but that just seems to have been a wish-granting stone, and not related to the transmutation of metals in particular.
The specific idea of the Philosopher’s Stone appears to come from the Middle East, and the first person to propose it is sometimes identified as the alchemist Jabir ibn Hayyan, or “Geber” in his name’s more European form, who was considered the Father of Arab Chemistry (despite the fact that he was likely Persian instead of Arabian).
Other devotees of the Philosopher’s Stone legend include Sir Isaac Newton and Nicolas Flamel, the latter of whom is mentioned as the Stone’s creator and a friend of Dumbledore’s in the first Harry Potter book. It seems rather likely in hindsight that Flamel was a writer and bookseller who pretended to be an alchemist in order to increase sales. In fact, that’s probably the more generous explanation, because otherwise he was presumably a jerk for hiding his discovery from the rest of the world.