Could any event have happened differently? Even if the universe was “inherently stochastic”, does this imply that events could have occurred differently? It seems to me that even inherent randomness would just result in true unpredictability in the future but nothing further would be implied.

Even if determinism was false and knowing every possible parameter and cause did not lead to complete knowledge of the future, would this actually imply that the way events turned out could have happened otherwise?

  • 2
    Technically, no. Metaphysical fatalism does not have to be implemented through causal determinism, although it is currently the only version with any following. The reason is that alternatives have a distinct flavor of mysticism, a la inexplicable fate or divine predestination.
    – Conifold
    Jun 15, 2023 at 9:31
  • What occurs does not depend on determinism but vice versa.
    – RodolfoAP
    Jun 15, 2023 at 10:05
  • Determinism is neither false nor true. Determinism is not a theory or a statement, just an abstract idea with no truth value. Jun 15, 2023 at 14:05
  • 1
    What does the OP mean by "could"? Metaphysical possibility? Logical possibility? Epistemic possibility? Generic possibility? Jun 15, 2023 at 16:21
  • Perhaps we should use a coin to find out. Jun 16, 2023 at 2:05

4 Answers 4


If you mean, "Is there an accessible world, accessible from ours that is, such that determinism is false in our world and in the accessible world things occur that don't occur in ours?" then I don't know that determinism has much bearing on this (if the other world contained the same exact sequence of events, and neither that world nor ours contained said sequence on account of determinism, I'm not sure how determinism is accessibly relevant).

You could move up to another level and ask, "Is there a world accessible from ours where determinism is false?" or then, "Do all worlds accessible from ours, even if they are nondeterministic worlds, contain the same exact events?"

If you mean, "Is it necessary that the events that have occurred, are the events that they are, regardless of determinism?" then in one sense yes, in another sense no: an event has to be what it is relative to its internal identity, but what events exist in the first place is not per se decided by external necessity such that different events could not have occurred.

It would also be helpful to include some reference-fixing for the word "determinism." The generic sense is mathematical: if you have a sequence of variables x over times tn, the value of x at tn is the source of the assignment of value to x at tn+1, e.g. if xt1 = 1, then there is some f(x) such that f(11) changes the upper 1 to something else as the lower 1 increases, etc. If f(x) can map specific inputs to only one output per case, strict determinism is indicated. But so whether f(x) can on some other metaphysical level be itself different from time to time or world to world, is an open-ended enough (schematic) issue such that it seems trivial that two worlds could diverge with respect to f(x) and so diverge per output, or two worlds could diverge on one level but due to subtle "course corrections" (e.g. deeper g(x)'s) they end up aligned on the direct level, etc.


The universe doesn't read philosophy journals. It does what it does, regardless of what philosophers may think.


Even if determinism was false [..] would this actually imply that the way events turned out could have happened otherwise?

The most common interpretation would be that yes, in that case events could have happened in different ways, and only happened the way they happened due to random factors.

But philosophically it depends on the way that determinism "was false" (or how "determinism" is defined in the question). Causal determinism is the most common meaning of "determinism". Causal determinism can be false in several ways which would still make some or all events determined by something.

Even if there were true sources of non-determinism in this universe, those could be too small, too few, too rare, too far away or too "regular" to make events turn out in different ways.

Predeterminism and fatalism are alternatives which do not necessarily require determinism. There can be more such similar nuanced theories that make events non-random yet not decided by the previous state either (but by anything else). All those could be called "Determinism without Causality".

So "events could not have turned out a different way" could be the definition of "causal and non-causal determinism". Then even if causal determinism was false, it is logically possible that non-causal determinism remains true.

Time-travelling in the science-fiction sense is one way of introducing non-causality into a universe, just to give a popular example, same as supernatural telekinesis, teleportation and such. Similarly, prophecy or otherwise "seeing" the future without inferring it from the present as in fantasy and mythology would introduce non-causality. Those could still mean that "things could not have turned out otherwise".

In physics, only quantum phenomena are considered to be possibly non-deterministic in a strict sense, even if many other events can only be described stochastically due to lack of precise measurement methods.

  • In short, the law of big numbers still would apply.
    – rus9384
    Jun 15, 2023 at 12:26
  • That is just one possible way (maybe the most obvious case, yes).
    – tkruse
    Jun 15, 2023 at 13:01
  • Predeterminism does require determinism. Otherwise the predeterminator could not make sure everything would proceed as planned. Fatalism requires indeterminism, otherwise Fate could not control the flow of events to reach the intended final goal. Both are imaginary ideas irrelevant in reality. Jun 15, 2023 at 14:01
  • @PerttiRuismäki Fatalism is a form of determinism: fate is the determinator instead of other processes.
    – rus9384
    Jun 15, 2023 at 15:38
  • @rus9384 Fate controls the events along the way towards a certain goal. A predeterminator designs everything beforehand and then presses PLAY. Jun 15, 2023 at 16:20

There is no "otherwise". All events have occurred this way instead of any other way. History is fixed, it cannot be edited, rewound or tried again. Only the future consists of uncertain possibilities.

Naturally the history could have turned out differently. All events in history were once mere possibilities in the future. Predetermination is a concept in religion only, not in science. A deterministic universe set up by an indeterministic predeterminator is an illogical, oxymoronic concept.

The current scientific consensus is that the Universe has evolved as a series of probabilistic events. Causality rules, but not with absolute accuracy. The inherent inaccuracy of all events enables evolution, the increase of entropy, the increase of complexity and the arrow of time.

  • I didn't downvote, but downvotes with no comments are a wasted opportunity, so if I was to guess at any issues with your answer: 1) "Naturally the history could have turned out differently". How do you know? 2) "The current scientific consensus is that the universe has evolved as a series of probabilistic events". Really? Do you have any references to support this claim? 3) "The inherent inaccuracy of all events". How can any event be accurate or inaccurate? Jun 15, 2023 at 15:56
  • 1
    @Futilitarian 1) The future can turn out multiple possible ways. No reason to assume that this hasn't been the case always. 2) We have no reason to assume a divine creator. Probabilistic evolution is the only alternative to deliberate design. 3) Quantum particles have some indeterminate properties that can be expressed only as probability distributions. Therefore all measurements and predictions are approximations or averages, never exact values. Jun 15, 2023 at 16:38
  • 1). My question was 'how do you know'? It doesn't help to simply restate the claim. 2) By this I assumed you were stating (by 'probabilistic') that the scientific consensus is that the universe could have evolved differently. If so, do you have any refs? 3) 'Predictions' and 'measurements' can be accurate or inaccurate as you say, but this is a different claim than your initial answer, ie. that events can be too. Jun 15, 2023 at 16:45
  • Re. 2). Are you sure you're not conflating the human view of 'probability' (when assessing the likelihood of unknown future events) with actual probability (whether events can unfold in any other way than the way they do?). Jun 15, 2023 at 16:54
  • @Futilitarian I am talking about the mathematical probability of an event unfolding in a certain way. Probabilities are always about future events, there is no comparison with "the way they do". Jun 15, 2023 at 17:08

You must log in to answer this question.