If we assume that there's a universe that is devoid of causality, and if we assume that it isn't eternally static, would that mean that everything can happen because there are no reasons inhibiting anything from happening?

  • Maybe you're a Boltzmann brain. How would you prove otherwise? en.wikipedia.org/wiki/Boltzmann_brain – user4894 Aug 5 '18 at 17:38
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    It's more likely that we're Boltzmann brains in this world as well. However, this question entertains the idea that there is a world identical to ours that lacks causal relations, regardless of whether or not that is a world invented by by a Boltzmann brain. – user3776022 Aug 5 '18 at 19:48
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    What does "causality" mean to you? When asking questions like these which take concepts to their utter extremes, we often find that the very precise nuances of a definition cause wide sweeping changes. It's why there's little agreement in such extremes. – Cort Ammon Aug 6 '18 at 3:52
  • Causality is the observation that everything that happens is preceded by a what appears to be its cause, which, to me, implies that nothing happens without a cause (that's why I assumed that a world without causes would be static). And if I imagine a world that is devoid of causes and yet does have effects, then, to me, it must mean that absurd things would happen in that world because nothing is related or dependent. – user3776022 Aug 6 '18 at 10:33
  • "..everything that happens is preceded by what appears to be its cause..." we do not live in a world even close to that now. I am a physicist, and I know that uncertainty (and unpredictability) is at the heart of quantum physics. – Carl Witthoft Aug 6 '18 at 13:36

If the world were without causality then it need not change in any way. It might fortuitously behave exactly as it does now. This is certainly a logical possibility.

If the world were without causality but none the less followed probabilistic laws - exhibited probabilistic regularities - then we could easily get by counting on such regularities if their probabilities were high enough to allow a certain level of predictability and computability in our experience.

If the world were without causality and also chaotic, so that there were complete unpredictability and uncomputability of subsequent given initial states, then not only would our experience be unpredictable and uncomputable but 'we' would disappear as persons or mental continuants (in any sense recognised now) because our mental life would be subject to the same unpredictability and uncomputability. And whatever the proper analysis of matter and mind, of physical and mental events, our bodies would cease to be continuants since (again in any sense recognised now) there would be the same complete unpredictability and uncomputability of subsequent given initial states.

Life would be rather different, if indeed it continued in any form.


Philosophers and scientists who reject the concept of cause as incoherent or who simply deny the existence of causal relations can, of course, treat the question as on a level with 'If we imagine a world without phlogiston, what would it be like ?'


Robert W. Batterman, 'Defining Chaos', Philosophy of Science, Vol. 60, No. 1 (Mar., 1993), pp. 43-66.

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  • The world could indeed work exactly as it does now, but without causality there is no reason to assume that it would. I was thinking that the following things could just as well happen in such a world: objects spawning into existence out of nowhere; deaths occuring despite there being no cause of death; and no guarantee guarantee of the arrow of time (entropy). My question pertains to the extent of what could happen, not whether the world could remain the same. My question has to do with what causality would inhibit in this world that would be possible in the other world. – user3776022 Aug 5 '18 at 19:42
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    @user3776022. I entirely agree but it is logically possible, that was the only point I was making. Very roughly, if a state of affairs can be described without self-contradiction then it is logically possible. My 'no change' scenario meets that condition. It's also logically possible for a cow to jump over the moon though I don't expect it to happen ;)- Best - GT – Geoffrey Thomas Aug 5 '18 at 19:52
  • I think that, in a causeless world, a cow could also spawn on the moon since no chain of events is necessary to transport the cow from point A (earth) to point B (the moon). – user3776022 Aug 5 '18 at 20:03
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    Point well taken - very good. Hume would certainly agree since he does believe that, since all events are distinct, any event or state of affairs can be followed by any other. He wouldn't expect the cow to spawn on the moon since it isn't among the regularities in our experience - but no more than that. Thank you - Best : Geoff – Geoffrey Thomas Aug 6 '18 at 5:34
  • I'm interested in sources for the argument that the world would be the same. Isn't this a case of "it it quacks like a duck..."? If the world is indistinguishable from one with causality, how do you falsify causality? – Tom Aug 6 '18 at 10:44

The question needs a better definition of terms. What exactly is it that you mean?

If you mean a complete disconnect between events so that there is no chain of causality, then the answer is simple: The world would not "be" in any sense that we could apply. Consciousness requires causality, otherwise no thoughts would arrive from any inputs to the system. No connected thoughts would arise and no "I" would be able to form.

Most things in the world, especially life and anything connected to it, are strongly linked and kept together by causality. This is the underlying structure of anything we call a system.

If you mean a weaker version in which causality (A -> B) continues to exist, but preconditions are weakening (i.e. B can also happen spontaneously) then we need to discuss the frequency at which spontaneous events happen. As long as they are strongly dominated by deterministic events, you would simply have a lot of chaos, the exact nature of which depends on the scale at which spontaneous events happen (quantum scale? micro scale? macro scale?).

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Causality is a concept, not something existing in the real, physical world. The closest you get is to look at physical processes which "cause" things to happen

Example: the constant pull of gravity on the apple weakens the bond to the tree, causing the apple to finally fall to the floor. It makes little sense to imagine an universe simply without the cause per se. You'd have to imagine an universe without gravity.

You then have to get rid of all physical processes that "cause" anything, ending up with an inert soup of stuff at best, and nothing at worst. In the previous example, instead of getting rid of gravity, you could get rid of the biochemical process which makes the apple prone to falling down, and so on and so forth. You'd still have to get rid of gravity as it causes an awful lot of things!

So, no, a world would not function without causality as expressed in physical processes.

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It seems to me the absurdity to most things isn't with our experience of some state of affairs, but how we're conceiving of them. It doesn't seem absurd to say "The world would be different if the world were different"; we just accept that it would be and can imagine that such differentness is possible. It's when we attempt to say "If I think of the world differently, I would think of the world differently" that a fundamental problem occurs. That is, we can't seem to easily part with the notion that how we think of the world is actually tied to how the world is. Humorously, we think that "If I think of the world differently, then the world would change."

As it is, if one holds that there is a distinction between causality and orderliness, then we have the possibility of a non-causal reality yet explainable in reasonable, useful terms.

Without such a distinction, the question would be literally absurd and attempts to directly answer would be incoherent; but given reality, we at least know certainly that there is order.

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Assuming you mean the philosophical misnomer "causality" meaning "being able to distinguish the past from the future" (as opposed to the physics meaning of the term), the question is ill-defined. The universe exhibits causality because it follows certain, very basic laws of probability -- high-entropy states of the universe are more probable than low-entropy ones, so when we keep observing more states, we're likely to observe higher and higher entropy states, which gives us a metric to distinguish the past from the future.

How exactly would you change these laws to produce a universe that doesn't follow the second law of thermodynamics? Until you precisely, mathematically answer this question, it's impossible to tell how your universe would look like.

If you mean causality in the physics sense, you would have a universe that behaves much like our own except faster-than-light travel is permitted.

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