I'm unsure how to approach David Gerrold's 1973 novel The Man Who Folded Himself. As a fan of time travel stories, I liked it. But the novel, I think, seemed to be designed as the ant-time travel books, as it takes a serious look -and make the claim -that temporal paradoxes are impossible. Which, of course, is what has kept time travel stories in books, TV and movies going for generations. Still, Gerrold appears to go with the Many Worlds Theory that dictates that there is an infinite number of alternate universes; that if time travel were indeed possible, you don't travel one linear road back and forwards, but that you wold "jump" one timeline for another, one that is exact in every detail, but subtly differences at the same time.
We meet Daniel Eakins in 1975. He's a young college student when he's visited by his only known relative, an older man named Uncle Jim. He tells Daniel that he's worth a lot of money and will increase his monthly allowance for living expenses as long as college student keeps a diary. Shortly after the visit, Uncle Jim dies, and Daniel inherits not money, but something called a 'Timebelt'. Dan quickly figures out the mysterious gift and begins to travel in time, He quickly meets an alternate version of himself, who accompanies him to a race-track where the pair make a fortune betting on horse racing. The following day, Daniel realizes that it is his turn to guide his younger self through the previous day at the races; through this and other events the time-travelling Daniel learns more about the belt, about the nature of the 'timestream', and about his personal identity. Daniel, then, repeatedly encounters alternate versions of himself, ultimately having sex with himself and beginning a relationship with himself. But he discovers, however, that his personal timeline has been changed, and has excised his childhood. He tries to repair that, and ends really far in the past that he meets a female version of himself named Diane. Of course, he has a relationship with her that produces a child.
And then things get even weirder.
Gerrold produces some interesting quandaries here, moral questions and ideas of what time travel represents and what us mere human might do with what Dan calls "God" like powers. His theories are logical, yet confusing at the same time. Of course I realized early in the book where the story was going, but that did not put me off. Time travel stories are inherently full of paradoxes, and despite the whole premise circles back on himself, I'm still curious where the Timebelt comes from -which is just the MacGuffin of the story; you're not suppose to know. Again, that does not decrease my enjoyment of the novel, but it's these small things that some times distracts me.
Note: While the book was written in 1973, it appears have been updated by Gerrold, once in 1983 (the edition I read) and again in 2003 for the e-book edition.