History Analysis / OntologicalInertia

What's the difference between Ontological Inertia and You Can't Fight Fate when we talk about time travel? Aren't they the same but more specific?

No, and it's possible the confusion stems from taking into account just the time travel element of Ontological Inertia while disregarding the rest. And, to a lesser extent, doing the same with You Can't Fight Fate.

Ontology is the philosophy of existing or, more accurately, being. Why, what, and how things exist and what is existing in the first place are questions this branch studies. Inertia can be described in very simple terms as the fact that objects keep behaving (from a Physics' point of view) the same way unless there's some kind of force applied to them that forces them to change their behavior. What do you get when you mix those two abstract concepts? Ontological Inertia -- things once born will continue existing and being themselves (with what properties they had from the beginning) unless some external force (either philosophical or physical) either modifies or destroys them. And they'll do so as long as their existence is independent of whatever created them. Say, a person's voice has NO ontological inertia since its very existence hinges upon the person making their vocal cords resonate. If said person stops doing so, their voice will cease existing. Conversely, people as a whole have ontological inertia since they don't die when their parents (i.e., what created them) die. Nor people will suddenly disappear just because someone stopped thinking about them.

So it could apply for a range of things, for everything, in fact. But, what about time travel? First, we have to define what things their existence we're discussing. Timelines exist. People and elements who affect and belong to said timelines exist. Actions that determine each unique timeline are made by those elements and people -- and such actions exist. If all of those things have ontological inertia, therefore once they are born they're independent of one another AND only change their nature when interacting with each other. In other words, if you kill someone, the timeline in which that person existed will not crumble just because said person died. If the timeline is erased from existence, people inhabiting it may still have versions of themselves inhabiting other timelines. When people interact differently, they'll create different timelines, thus not affecting the initial timeline, just causing it to diverge into alternate paths. People who belong to the timeline, that is. It can also happen that people don't (read can't) interact differently because of all of the tiny factors and previous interactions that determined present interactions which, in turn, will mold future interactions. It might be Fate, but it can also be due to probabilities. Basically, the world interacting with itself in the most probable ways.

When we talk about external forces which may include people jumping between timelines OR people from different points in a given timeline, something similar will happen. People who belong to the timeline can't change their ways because they are intertwined with the rest of the elements and actions that compound the timeline. IF a timeline has ontological inertia, external elements will hold no sway over the network of interactions because they don't exist. They don't belong to the timeline, thus they cannot impact it nor interact with it. Any change (modification/creation/destruction) will be canceled out.

Look it this way: the timeline has already happened when you travel from a different point in it or from another timeline. So, the events (actions) that determine the timeline have been born already and their existence is no longer dependent on whatever provoked the events. They will carry on because they have ontological inertia. So no matter what the time-travelers do, it will not impact any event because while the events' creation happened due to past interactions, the events' continued existence does not depend on them anymore. Only things belonging to that point in the timeline (thus existing) can change them in any way. But, again, time travelers and their actions don't exist for the timeline.

Summing up — All events in a timeline have already happened for someone external to the timeline (and external things don't exist for the timeline). Because the events happened, they will keep existing regardless of what events led to them in the first place.

As for You Can't Fight Fate, well, it can be justified because of all I did just say but is only one reason among several possible causes. And that trope is not restricted to time travel either. It's based on some abstract concept called Fate. Fate is what happens when events are predetermined notwithstanding whether what caused them still exists, whether some events can be truly, directly caused by past interactions (internal forces), or whether whatever external forces pass by. You can think about it as if cause and consequence are inverted. Say I'm fated to sing a song today. Because I will sing a song today, I must have learned its lyrics beforehand. If I wasn't fated, well, one day I will decide to learn some song's lyrics and then decide, again, to sing it sometime afterward. Or I can just not sing it. The point is, without Fate, my past actions set the basis of what I'll possibly do in the future but it's me who ultimately decides. When Fate exists, the predetermined events (me singing a particular song) are what causes the past events in my life to build up and allow for the predetermined ones to happen.

It's quite different from Ontological Inertia since Fate has inherently nothing to do with the nature of being and things keeping existing due to inertia. They are not mutually exclusive, though, because OntologicalInertia can be used to justify YouCantFightFate. I regard them as Sister Tropes instead of Sub Trope and Parent Trope. Specifically, they'll be a case of:

It is possible Fate is the thing that provides some or all of the elements of a given timeline their ontological inertia. In the first case, both will merge into a stable timeline. In the second, it's not the timeline itself what has ontological inertia but rather some specific elements of the timeline (mainly events/actions, but people and objects are not excluded).

Summing up (overall) — Essentially, OntologicalInertia and YouCantFightFate are Sister Tropes that share the same function, i.e., to explain why the characters can't change the past. OntologicalInertia explains it because external things don't exist for a timeline with ontological inertia and, thus are unable to affect it. YouCantFightFate, on the other hand, explains it because it was the (predetermined) future what caused the past to be like that and not the other way around. They may overlap and OntologicalInertia can be used to justify YouCantFightFate.

So it could apply for a range of things, for everything, in fact. But, what about time travel? First, we have to define what things their existence we're discussing. Timelines exist. People and elements who affect and belong to said timelines exist. Actions that determine each unique timeline are made by those elements and people -- and such actions exist. If all of those things have ontological inertia, therefore once they are born they're independent of one another AND only change their nature when interacting with each other. In other words, if you kill someone, the timeline in which that person existed will not crumble just because said person died. If the timeline is erased from existence, people inhabiting it may still have versions of themselves inhabiting other timelines. When people interact differently, they'll create different timelines, thus not affecting the initial timeline, just causing it to diverge into alternate paths. People who belong to the timeline, that is. It can also happen that people don't (read can't) interact differently because of all of the tiny factors and previous interactions that determined present interactions which, in turn, will mold future interactions. It might be Fare, but it can also be due to probabilities. Basically, the world interacting with itself in the most probable ways.

Ontology is the philosophy of existing or, more accurately, being. Why, what, and how things exist and what is existing in the first place are questions this branch studies. Inertia can be described in very simple terms as the fact that objects keep behaving (from a Physics' point of view) the same way unless there's some kind of force applied to them that forces them to change their behavior. What do you get when you mix those two abstract concepts? Ontological Inertia -- things once born will continue existing and being themselves (with what properties they had from the beginning) unless some external force (either philosophical or physical) either modifies or destroys them. And they'll do so as long as their existence is independent of whatever created them. Say, a person's voice has NO ontological inertia since its very existences hinges upon the person making their vocal cords resonate. If said person stops doing so, their voice will cease existing. Conversely, people as a whole have ontological inertia since they don't die when their parents (i.e., what created them) die. Nor people will suddenly disappear just because someone stopped thinking about them.

Ontology is the philosophy of existing or, more accurately, being. Why, what, and how things exist and what is existing in the first place are questions this branch studies. Inertia can be described in very simple terms as the fact that objects keep behaving (from a Physics' point of view) the same way unless there's some kind of force applied to them that forces them to change their behavior. What do you get when you mix those two abstract concepts? Ontological Inertia -- things once born will continue existing and being themselves (with what properties they had from the beginning) unless some external force (either philosophical or physical) either modifies or destroys them. And they'll do so as long as their existence is independent of whatever created them. Say, my voice has NO ontological inertia since its very existences hinges upon me making my vocal cords resonate. If I stop doing so, my voice will cease existing. Conversely, people as a whole have ontological inertia since they don't die when their parents (aka what created them) die. Nor people will suddenly disappear just because someone stopped thinking about them.

Summing up (overall) — Essentially, OntologicalInertia and YouCantFightFate are Sister Tropes that share the same function, i.e., to explain why the characters can't change the past. OntologicalInertia explains it because external things don't for a timeline with ontological inertia and, thus are unable to affect it. YouCantFightFate, on the other hand, explains it because it was the (predetermined) future what caused the past to be like that and not the other way around. They may overlap and OntologicalInertia can be used to justify YouCantFightFate.

Ontology is the philosophy of existing or, more accurately, being. Why, what, and how things exist and what is existing in the first place are questions this branch studies. Inertia can be described in very simple terms as the fact that objects keep behaving (from a Physics' point of view) the same way unless there's some kind of force applied to them that forces them to change their behavior. What do you get when you mix those two abstract concepts? Ontological Inertia -- things once born will continue existing and being themselves (with what properties they had from the beginning) unless some external force (either philosophical or physical) either modifies or destroys them. And they'll do so as long as their existence is independent of whatever created them. Say, my voice has NO ontological inertia since its very existences hinges upon me making my vocal cords resonate. If I stop doing so, my voice will cease existing. Conversely, people as a whole have ontological inertia since they don't die when their parents (aka what created them) die.

So it could apply for a range of things, for everything, in fact. But, what about time travel? First, we have to define what things their existence we're discussing. Timelines exist. People and elements who affect and belong to said timelines exist. Actions that determine each unique timeline are made by those elements and people -- and such actions exist. If all of those things have ontological inertia, therefore once they are born they're independent of one another AND only change their nature when interacting with each other. In other words, if you kill someone, the timeline in which that person existed will not crumble. If the timeline is erased from existence, people inhabiting it may still have versions of themselves inhabiting in other timelines. When people interact differently, they'll create different timelines, thus not affecting the initial timeline, just causing it to diverge into alternate paths. People who belong to the timeline, that is. It can also happen that people don't (read can't) interact differently because of all of the tiny factors and previous interactions that determined present interactions which, in turn, will mold future interactions. It might be Fare, but it can also be due to probabilities. Basically, the world interacting with itself in the most probable ways.

As for You Can't Fight Fate, well, it can be justified because of all I did just say but is only one reason among several possible causes. And that trope is not restricted to time travel either. It's based on some abstract concept called Fate. Fate is what happens when events are predetermined notwithstanding whether what caused them still exists, whether some events can be truly, directly caused by past interactions (internal forces), and whatever external forces pass by. Or you can think about it as if cause and consequence are inverted. Say I'm fated to sing a song today. Because I will sing a song today, I must have learned its lyrics beforehand. If I wasn't fated, well, one day I will decide to learn some song's lyrics and then decide, again, to sing it sometime afterward. Or I can just not sing it. The point is, without Fate, my past actions set the basis of what I'll possibly do in the future but it's me who ultimately decided. When Fate exists, the predetermined events (me singing a particular song) are what causes the past events in my life to build up and allow for the predetermined ones to happen.

It's quite different from Ontological Inertia since Fate has inherently nothing to do with the nature of being and things keeping existing due to inertia. They are not mutually exclusive, though, because OI can be used to justify YCFF. I regard them as Sister Tropes instead of Sub Trope and Parent Trope. Specifically, they'll be a case of:

Summing up (overall) — Essentially, OI and YCFF are Sister Tropes that share the same function, i.e., to explain why the characters (external things, non-existing for a timeline with ontological inertia) can't change the past. OI explains it because of what I put within the parentheses. YCFF, on the other hand, explains it because it was the (predetermined) future what caused the past to be like that and not the other way around. They may overlap and OI can be used to justify YCFF.

No, and I think the confusion stems from taking into account just the time travel element of Ontological Inertia while disregarding the rest. And, to a lesser extent, doing the same with You Can't Fight Fate.