Tenet (Part III)
TENET (Part III) The Theory of Time Travel
With all this in mind, this brings me to my main complaint and main compliment about the film, which regard the worldbuilding.
My main complaint is that it is time travel film. My main compliment is that is a cleverly done time travel film.
Now, be it known that, as an old hand in the science fiction field, as I said, I have read my share of time travel stories, perhaps one too many, and thought out it, or overthought it, and there are certain themes and conceits to which I have learned to take a hearty dislike.
In his essay “The Theory and Practice of Time Travel” appearing in his anthology ALL THE MYRIAD WAYS, Larry Niven states bluntly that he hates sideways in time stories.
He gives the reason that it belittles the difficulty of making the right decision when the decision is crucial, because if both decisions are always made in two different branches of time, all decision-making is in vain. By hypothesis, it is illusionary, hence meaningless.
In effect, a myriad worlds multiverse mocks free will. No matter what you decide, nor how hard the effort to make the decision was, you also did the opposite, so you could have saved yourself the trouble.
Niven’s reason is pellucid: if every coin toss ends up heads AND tails, then likewise every attempt to climb the Matterhorn, cross the Atlantic, split the atom, or land on the moon also ends in success and failure, no matter what you do or fail to do. Every Judas or Benedict Arnold is also Saint John and George Washington.
Larry Niven is then a masterful enough writer of science fiction to sit down and pen an example of exactly what he means, drawing out the realistic and nihilistic consequences of sideways-time branching in the chilling little short story from which the anthology takes its name.
In the spirit of Larry Niven, let me bluntly state that I hate time travel stories, because, by the very nature of time travel, either free will is mocked, or cause and effect is mocked, or both; in any case all decisions and actions taking place in the plot of such a story are, by hypothesis, illusionary, hence meaningless, and all in vain.
Time travel, in order to be time travel properly so called, must allow the time traveler to change the past and to visit hence foreknow the future.
The whole appeal, the whole point, of time travel is wish fulfillment. The one thing we humans cannot do, and can never do, is change the past and know the future. Such stories are speculations, or logic puzzles, about what might happen if we could.
In human experience, the past is fixed and the future is in flux. Because the future is in flux, we cannot foreknow it, not with certainty. We can guess or glimpse the future, perhaps, through human reason or divine revelation, or see shadows of what may be: but this does not fulfill the wish to escape the constraints of the human condition, and to have tomorrow’s winning lottery numbers today. One needs no fancy time-travel machine to visit a future that might be possible: one can dream up possibilities, as many as might be wished, sitting in an armchair.
Time travel, in sum, is the wish to change what cannot be changed, and to know what cannot be known.
The paradox is that if the past can be changed, then so can the present and the future, since these are determined by the past; therefore everything can be changed; whereas if the future is fixed, so must be the present and past, since these determine the future; therefore nothing can be changed.
Hence the problem is that time travel stories can never carry out their speculation to a logical conclusion, because the logic leads to no conclusion. No logic means no story.
And from the point of view of storytelling, if the hero has a time machine, he can visit any past scene and undo the consequences, and revisit any future scene, to learn firsthand the results of his attempt, and see any unexpected surprises beforehand. He can consult his future self to learn what he will eventually decide.
Editing the past gives him infinite power, and visiting the future gives him infinite knowledge. But no one can write a drama starring an infinite hero who faces no challenges.
A story, to be a drama properly so called, and not simply a descriptive vignette, must have a character whose acts select between the options the plot offers him, and the story must have a plot that limits the character’s options of action. Even if the viewpoint character is a passive observer, a Professor Aronnax or a Dr. Watson, he must be observing the active protagonist, a Captain Nemo or a Sherlock Holmes, whose decisions drive the plot.
Philosophically speaking, a drama must be both determinist and indeterminist: determinist, because the plot must follow the constraint of the law of cause and effect; and indeterminist, because the character arc must follow from the liberty of the law of free will.
But if changing the past and foreknowing the future are open options in the story, drama is impossible: for no action has consequences if the hero can revisit any scene in his past and, armed with perfect foreknowledge, alter the outcome to suit himself.
In which case the story can have no plot, for a plot consists of the consequences following the character’s decisions and actions.
Likewise, foreknowing the future renders free will meaningless. In which case, once again, the story can have no characters, for a puppet whose act are predetermined is not a character, that is, not a character in a drama.
So, whatever the reality of determinism and indeterminism as a philosopher might debate the issue, as a matter of the practical craft of storytelling, a story must have a character whose indeterminate hence free choice has determinate consequences from which he is not free. Otherwise, there is no drama, no tale.
For these reasons, time travel stories are always a cheat.
Such a story can be a clever cheat, and an entertaining one, but it is still a cheat: because the promise of time travel has to be limited or hobbled to make the character lack infinite power and infinite foreknowledge. The time traveler has to be allowed to change some past events, and not others, and foresee some future events, and not others, in order for him to be human enough and limited enough to face a challenge from which alone drama springs.
In other words, in order to tell a story about time travel, the hero has to be allowed to have a time machine, but not be allowed to use it.
So, time travel stories, by their nature, threaten to be as unworkable and unsatisfying as one that ends with the main character walking up back in the black-and-white world of Kansas and discovering that all was a dream.
Unless one learns some life changing moral lesson in the dream — such as that there is no place like home — having it all be a dream is a cheat. It means that all the dangers faced were no threat, and any victories were unreal. And Mrs. Gulch is still sending the sheriff tomorrow to have your dog destroyed.
I use this example on purpose, because it is a counter-example: WIZARD OF OZ is rightly one of the best beloved films of all time, and it has what should be an unworkable and unsatisfying ending, namely, that Oz does not exist and nothing done there was real. But the final plot twist in the final scene is, as we all recall, that the farmhands, friends, and helpful wandering magicians were there in Oz, merely disguised as fantasy. The point of the story was not to liquidate the witch, but to learn not to run away from home, which was, after all, the grave and selfish error at the beginning of the film that sent the protagonist into dreamland.
Thematically, is it not a cheat at all. The film has a theme that G. K. Chesterton could have penned: the point of the drama was not to gain brains, heart and courage for your friends, but to discover that, like they did, what Dorothy falsely thought she was lacking was with her always, found in her own backyard. In a sense, Dorothy is right when she says it is a really real place: Oz is Kansas, if seen rightly.
In other words, by brilliant craftsmanship, the filmmakers of Oz made an element of storytelling that normally, by rights, should and often does drain all drama from the work, work to advantage.
As with dream-dramas, the art of telling a time travel tale is the art of turning the element that, by rights, should drain all drama from the work, into an element that works to the story’s advantage.
Let us turn now to the theory and practice of time travel storytelling:
In terms of the theory, time travel is impossible as a matter of logic.
A simple thought experiment can show why: imagine the time traveler throwing the switch to turn on his time window which is focused one moment back in his past. If he sees his own past hand reaching to flip the switch, he reaches back into the window and grabs the wrist, preventing the time window from opening, which prevents him from reaching back and grabbing his past wrist. If he sees his past wrist being grabbed, he reaches past the arm wrestling and flips the switch.
If the thought experiment involving arm wrestling is too messy, the same thought experiment can be set up with a spring-loaded power switch leading to the time machine, whose wires run one second backward in time. Place the time machine on top as a deadman switch. If the power is on, the time machine launches and disappears, releasing the spring and opening the switch, which cuts the power one second in the past, which prevents the time machine from launching. If the time machine does not launch, however, then the switch is closed and the power is on, and the time machine launches.
Or, if the idea needs to be simpler and more murderous, ask what happens if the Time Traveler’s first act is not to visit the far future year of AD 803702, but to go back before his father’s birth and kill his grandfather. This thought experiment is commonplace enough (at least, commonplace among those of us whose free time allows us to ponder and debate such folderol) that it has a standard name: The Grandfather Paradox.
Now, no doubt the alert reader has already thought of the three basic ways to build a world to avoid or elude the Grandfather Paradox, which would preserve the appearances: a fatalistic universe, where free will is illusion; a chaotic universe where cause and effect is illusion; and myriad branching universe where both are illusion.
A prime example of the first is ‘By His Bootstraps’ by Robert Heinlein; of the second is ‘The Men Who Murdered Mohammed’ by Alfred Bester; of the third is ‘The Man Who Folded Himself’ by David Gerrold.
Any number of stories utilize uncounted halfway explanations drifting somewhere between fatalism, acausal chaos, or multiversal myriadism, but doing so inconsistently. The number of inconsistent explanations is limited only by the imagination of the science fiction writer, an ilk justly famed for their imaginative powers.
And, of course, the most common option of all is to explain nothing, by not bringing the topic up.
This, then, is the practice of how to write a story that, by rights, should be impossible to write. Let us discuss each in turn.
About John C Wright
John C. Wright is a practicing philosopher, a retired attorney, newspaperman, and newspaper editor, and a published author of science fiction. Once a Houyhnhnm, he was expelled from the august ranks of purely rational beings when he fell in love; but retains an honorary title.
