I started by thinking about beta testers. What are beta testers? Instead of testing something 100 times, you could hire 100 people to each test it once. Of those 100 people, some may be in a hurry, some may be distracted, some may misread the instructions, just as you might if you did it 100 times. It’s like rolling a die 100 times, or rolling 100 dice once.
Other people might just be you in different situations. If you were late for work. If you were on holiday. If you were born in a different family. In a different time. So I thought, what if everyone were me, running through this world at different times, but at the same time?
Then I discovered this short story, The Egg by Andy Weir: The Egg which is similar to what I was thinking, but without the maturing and god parts. It really does seem like no matter what you think of, someone else has already thought of it. So, is there a name for this philosophy?
Well, in Neoplatonism every human soul - well everything at all, really - is an “emanation” or aspect of the One, which is the only thing that really exists, but is beyond description or comprehension. You also have something similar in Germanic idealist philosophy, such as that of Hegel (and neo-Hegelians such as Bradley and Collingwood), which is, to a large extent, a sort of historicized version of neoplatonism. I don’t know if that is quite the same as what you are getting at, however.
What you say is also reminiscent of Richard Feynman’s (or rather, IIRC, his teacher’s) idea that all electrons might really be the same electron traveling in space and time, like Dr Who, and constantly crossing through the present moment in different places and different directions. Feynman rejects the idea, however.
I should have known this would happen. I’ve been working on a novel, on and off, for the past few years, and each chapter is about a person in wildly different times and places and personalities. Until someone remembers . . . and is labeled psychotic. I’m even writing it in second person.
Having now read the story linked by the OP, there is a lot of pure Plato in there too: not the idea that every person is the same person traveling back and forth through time, but the idea that when a person is born, it is from a pre-existing soul from ‘heaven’ being incarnated, and that soul in heaven knows the true reality, but forgets that knowledge when it descends’ into a physical body. Plato also probably held that the soul returns to heaven and regains its knowledge when the body dies, but I do not think he anywhere suggests that the same soul might be incarnated more than once. (From his perspective, being incarnated was a bad thing.)