Is there a cogent argument against the principle of sufficient reason?

Question

As far as I can see, there are no significant arguments against the principle that all events have a cause, which is to say the principle of sufficient reason. (It's important to note that the seemingly identical idea that all effects have causes is a circular argument based on the mutual definitions of "cause" and "effect".) While the idea seems intuitively obvious and therefore self-evident, we hold many counter-intuitive ideas to be true.

Has anyone proposed a serious argument that events sometimes are not caused?

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Clarification: The question title may be misleading because it suggests that the question is an epistemological one, but my actual question is metaphysical (or perhaps even ontological). Whether or not we can always (or even ever) know the sufficient reasons for an event is beside the point (unless it can be shown that we always can know the cause of every event).

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I've been asked to define what I mean by an event. That's a bit more than I can take on at the moment, but the Stanford Encyclopedia of Philosophy suggests that we have a "prima facie commitment to entities of this sort." If I had to suggest a definition, I'd say an event is a discrete observation or inference about a period of time. That I was married is an event that was observed by many people. That the sun was formed is an event inferred by the current state of the universe. Of course, that definition has an assumption buried in it that makes the question less interesting: inference implies causation. So we need to find a definition that conforms to our intuition of what an event is, but does not implicitly conform to our intuition that events are caused.

For the purposes of this question, the best definition of an event is that it is something that happens. Do things happen for which there is no cause?

Answer 1

Actually, there are a number of significant arguments against the principle of sufficient reason; you can find them in Sextus Empiricus, Hume, Wittgenstein and Nāgārjuna to name but a few.

In terms of accessibility, I suppose I'd recommend starting with Hume's view, which you can read about in "David Hume: Causation" (Internet Encyclopedia of Philosophy) or "Kant and Hume on Causality" (Stanford Encyclopedia of Philosophy), followed by Wittgenstein on rule-following, which you can read about in Wittgenstein on Rules and Private Language (Wikipedia article about Saul Kripke's book).

Of course, if you are more familiar with classical literature, you can check out Sextus Empiricus (Outlines of Pyrrhonism, Book III, if I recall correctly); similarly, if you are more familiar with Buddhist philosophy, you can begin with Book I of the Mūlamadhyamakakārikā.

EDIT:

I should clarify that none of these thinkers suggest that there are events that are uncaused; this is one of the positions that Nāgārjuna explicitly rejects in the first verse of the Mūlamadhyamakakārikā. Rather, each calls into question the notion of causality, and attacks either the notion of "sufficiency" or the notion of "reason" with regard to the matter.

Answer 2

I'm not sure the idea of "reason" is sufficiently specifiable for the question to make sense. I am not familiar with arguments that events are not caused, but there are at least a couple of reasons to be worried.

Since quantum mechanics seems non-deterministic, one could argue that things do indeed happen without reason...or one could broaden the definition of "things" and "reason" so that QM fits nicely within the box.

Also, we don't have direct access to causes; all we have is sense data about what is happening. A cause is thus a generalization of a statistical measurement on sense data; a reason invokes the appropriate conditions and causes. However, in certain cases we have dreadfully little statistical data (e.g. how many universe-creation-events have we witnessed, or does it even make sense to think of this as an event?), so there is dramatically less reason to think that all events are caused in such situations.

Answer 3

It's difficult to know how an argument against the principle could begin. As humans, we seem to have a deeply ingrained model of the universe that implies all events have causes. Our instinct seems to be to assume a cause without having any explicit evidence that a cause can even exist. Consider the case of the the beginning of the universe. If any event is likely to be causeless, it is that event. And yet, there exist any number of theories that attempt to explain the Big Bang. Our intuition that everything has a cause seems to literally have no bounds—not even the universe can contain it.

One avenue of attack would be to suggest that our model of causation was itself uncaused and therefore it is not reliable. But that naturally leads us to question how we can make an argument against the idea of causation based on the principle of sufficient causes. (I am reminded of Plantinga's concept of defeaters here.) And more damaging, the argument, if it succeeds, merely shows that we can't trust our intuition, not that our intuition is false. It would be an attack on the epistemological question, not the metaphysical one.

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We aren't asking about Determinism, which says that if we know the current state of the universe and the rules that govern it we can (in theory) know every other state of the universe. There are certainly good arguments against that hypothesis. And if we could find an argument against the "principle of sufficient reason", we could debunk determinism easily enough. (If things just happen, we can't very well predict them.)

But showing that determinism is a bad model for reality has no bearing on this question at all. If I find a coin on the ground with heads showing, there are any number of ways it could have gotten there. But since we all accept the principle of sufficient reason, we all agree that something must have caused the coin to be there and we all reject the idea that coins spontaneously appear on the ground. Nor is it a problem that the coin is showing heads rather than tails because there exist approximately equal number of causes that result in that state as opposed to the other. A coin carefully balanced on its edge excludes a number of causes, but we are certain that we will eventually find some set of causes that result in that state even if can never be sure which particular cause actualized it.

Quantum mechanics is a model of parts of the universe that suggests a number of counter-intuitive results, but as far as I can tell people who explore the model still expect to discover some set of causes for everything they observe. A simple test of that assertion is to imagine what will happen if a scientist notices something that the theory does not predict. They will likely redo the experiment, reinterpret their results, adjust the theory, or some combination of the above. What they won't do is say, "Oh well. Things sometimes happen that don't have any reason at all to happen."

Summary

There's no evidence that disproves the principle of sufficient reason (and precious little that proves it), so we can continue to behave as if it is true without fear of behaving irrationally.

Answer 4

If a cause is itself an event, every cause must also have a cause.

There cannot, then, be an uncaused cause but instead an infinite regress. If, on the other hand, there is an uncaused cause, the Principle of Sufficient Reason is false.

But perhaps a cause is not an event.

Answer 5

The principle of sufficient reason demands that everything must have a reason. So what is the reason for the principle itself? There isn't one - it's simply stated as a brute fact.

I'm consistently bewildered that such a gaping hole goes unremarked upon. The principle immediately fails when it's turned in upon itself.

That doesn't mean it should be tossed out, but it's clear that with a flaw as enormous and self-negating as this it cannot be anything more than a rule of thumb.

Answer 6

Not only is there, some philosophers and it seems most physicists say the original PSR is invalidated by quantum mechanics. Only a weaker version can be defended. One that says roughly "if there is no sufficient reason, there is a sufficient reason for why there is none".

R. Kane A philosopher

"Not every sub-atomic event has a sufficient, i.e., causal, explanation. But when an event does not have a sufficient explanation, it is assumed that there must be a sufficient explanation for why it does not have a sufficient explanation. This latter explanation lies in the laws of quantum physics themselves which yield the uncertainty principle and thereby account for why some events are uncaused" [1]

Robert Nozick Another philosopher

“…it would be foolhardy indeed to place any significant weight upon the necessity or even truth of SR. This century has presented us with a well-developed physical theory, quantum mechanics, that does not satisfy SR. Moreover, theorems show that any theory that retains certain features of quantum mechanics also will not satisfy SR.” [2]

(He also states the PSR doesn't "self-subsume" to provide its own explanation. The PSR only guarantees a sufficient reason/cause, not what it is. This is a purely philosophical argument, different than the main content of my post. It also does not rule out the PSR, rather the PSR needs another sufficient reason to justify itself.)

John Conway A physicist

video: "...this already suggests and in fact the philosopher Robert Nozick sort of thought it proved that how can I say it, well he thought it proved that Leibniz's principle of sufficient reason was false, you will remember Leibniz's principle of sufficient reason I hope, nothing ever happens says Leibniz without there being a sufficient reason why the thing happens and not something else happens. We'll strengthen this so that it really does disprove Mr. Leibniz's principle of sufficient reason. We'll show eventually that not only doesn't - you see what this shows us, that there doesn't exist a function of direction which tells what the spin is until you make the measurement just not there, and in any way I think of it the particle answers you on the fly"

In standard quantum theory, to explain certain experimental results, one must assume objects did not have definite physical states prior to the experiment. This builds off off a century+ of experiments and works by physicists like John Bell, Kochen, and Specker, and later also Conway (above). Assuming locality/local causality - which is very hard to give up for philosophers and physicists (and everyday folk). So only a weaker version of the PSR survives, as highlighted in the first two quotes.

Some philosophers and physicists may disagree, but what I've written seems to be the currently best defended take on things.

Answer 7

If you accept some radical Platonism such as Teg Mark's contemporary Mathematical universe hypothesis, then it implies that the classic necessary truth PSR (principle of sufficient reason, dependent origination/arising, etc) doesn't hold within our contingent (efficient) physical world. According to MUH:

Tegmark's MUH is: Our external physical reality is a mathematical structure. That is, the physical universe is not merely described by mathematics, but is mathematics (specifically, a mathematical structure). Mathematical existence equals physical existence, and all structures that exist mathematically exist physically as well. Observers, including humans, are "self-aware substructures (SASs)". In any mathematical structure complex enough to contain such substructures, they "will subjectively perceive themselves as existing in a physically 'real' world".

The theory can be considered a form of Pythagoreanism or Platonism in that it proposes the existence of mathematical entities; a form of mathematical monism in that it denies that anything exists except mathematical objects; and a formal expression of ontic structural realism.

Some certain weirdness in modern quantum mechanics which may be formulated and explained by abstractly invented math but seemingly contradicts our everyday experience tends to lead to such an extreme Platonistic view, and in fact Teg Mark is a contemporary physicist. Of course there're numerous arguments against MUH due to its apparent radicalness, but once you hold such position, and since math structure is essentially an axiomatic deductive system, so at least the axioms and its associated definitions don't have any sufficient reason to be accounted for within this world (system), which is certainly not what Leibniz conceived to be possible in his mind when he coined this principle. For him, MUH axioms are just like another form of his "first cause" beyond this contingent world...

Answer 8

A bit upset to see nobody speak a word here about Schopenhauer. He wrote his doctoral thesis on the scope and limitation of the PSR. It takes familiarity with Kant, but if you have that then it is worth reading it. It's called On the Fourfold Root of the Principle of Sufficient Reason. I also just wrote a blog post about it here.

Answer 9

The cogent argument is from physics: The decay of a given radium atom has no cause, it is a probabilistic event. But quantum mechanics (QM) gives the probability of decay of a given atom from a sample of radium atoms, which all have been prepared the same way.

According to the Copenhagen interpretation of QM there are no hidden parameters which give a sufficient cause - not to name a sufficient reason. Since this conclusion has been stated about a century ago, all efforts to find a better theory with hidden variables have ended unsuccessfully. Nevertheless the search goes on.

History shows that questions like these cannot be decided on the basis of philosophical principles. The range of philosophical a priori claims is limited and has to be determined in each single case.

Answer 10

Has anyone proposed a serious argument that events sometimes are not caused?

David Hume was unimpressed with the principle of sufficient reason. It was not so much that events sometimes are not caused, but that the effects of a given action can never be known in advance. Prediction is impossible.

Hume’s example was a hypothetical game of billiards. (Hume, David. 1902. An enquiry concerning human understanding, 2nd Ed. L.A. Selby-Bigge, ed. http://www.gutenberg.org/ebooks/9662, §25). His scenario assumes an observer who, in advance of an observation, knows almost nothing about the world, even about the effects of gravity.

I disagree with Hume about this. But his thinking stands as an example of a major philosopher who thought the principle of sufficient reason as useless.