I was reading on arguments for the existence of God and came across the Principle of Sufficient Reason (PSR) which describes that everything must have a sufficient cause/reason to exist. Looking at the definition of the PSR, empirical science is basically a representation. That is, we want an scientific explanation or a reason why something acts the way it does and more importantly, we have broad questions like what caused the Big Bang, or what defines existence for example.

Is it possible that the PSR is wrong and that some things can never be explained or that the PSR is right and we just haven't had the means or foresight to find a valid explanation for existence?

Thanks for reading.

  • Energy can not be create or destroyed. So PSR seems to be true for everything that changes today but how did energy start to exist? If PSR is true, what is the PSR of god or the universe? We as humans have no explanation how the first thing became or what the reason for it was. So we cant know for certain if everything is according to PSR
    – yamm
    Mar 26, 2015 at 12:46
  • Something that is said to be caused, is usually said to be caused not by itself, but by some other. Thus, for something to have no cause, is to be not caused by some other; and if we require strict adherence to the principle of sufficient reason, we can then stipulate it must be its own cause. This is outlined in Aristotles Metaphysics, and leads to his notion of substance. Mar 26, 2015 at 13:48
  • The entities the question is about are so fundamental they are on the verge of anything one may comprehend at all. Still almost to the very edge of it we may trace a (non-rigorously defined) hierarchy where one thing is considered more fundamental than another thing in various senses (one of these senses being (related to) causality). Mar 27, 2015 at 7:28
  • Hi, is this related to determinism ? If existence is deterministic, then an initial 'spark' (big bang/ or there wasn't a 'beginning' because things have always been) would mean the unfolding of reality is determined and everything that happens will have a cause. If existence isn't deterministic then that imples things can happen either for a non-physical reason (eg free will / dibvine intervention etc) or no reason at all ? Mar 27, 2015 at 11:34
  • "Is it possible that the PSR is wrong and that some things can never be explained..." i suppose that the PSR fails to explain the existence of God. i think that's the whole idea behind God is that nothing explains the existence of God. Apr 1, 2015 at 3:10

2 Answers 2


PSR is not a universally accepted concept in ontology, so it is entirely rational to consider the idea that it might be wrong.

It is worth noting that the specific example of the existence of God is worded as an ontology phrase ("is"), while you tagged the post with epistemology ("behaves like"). PSR is usually thought of as a thought process, and applying it ontologically is a very very very tricky process. From what I have read, its primary purpose was to work the opposite way: we can model a "thing" as a "thing" if there is sufficient behavioral evidence to justify the effort of calling it a "thing." It was not originally used to argue that that thing "is," but rather to argue that it was effective to act as though a thing "is."

There have been some ontological arguments using PSR (Wikipedia lists Kant's "arrow of time" as an example). However their universal acceptance is far from universal.

  • So the PSR is indeterminate since there isn't an sufficient explanation to argue for it nor refute it. However, are you suggesting (because I am slightly confused) that the PSR is a concept that asserts that every object has a sufficient explanation as to why it exists?
    – tommark
    Mar 28, 2015 at 5:37
  • I would say it is indeterminate because it, itself, is not complete enough to stand on its own. PSR applied to ontology or PSR applied to cognitive processing would be a complete enough entity to discuss if it is valid or not. However, there is not a consensus amongst philosophers as to what the "correct" application of PSR to ontology is, so without picking an arbitrary application, it is difficult to discuss the truthfulness of it.
    – Cort Ammon
    Mar 28, 2015 at 6:42

There are many formulations of the PSR, just as there are many formulations of just about any other principle or argument in philosophy. Some versions seem very implausible, while others are more well-accepted. The short answer is that no formulation is universally accepted - so yes, it is certainly possible that the PSR, in any of its formulations, is false, just as it is possible that any of the formulations is true. But I'll give a few examples of what I'm talking about.*

One version of the PSR, inspired by Spinoza and Leibniz, says something to this effect: "for everything that is so, there is a sufficient reason for its being so." That is, every proposition has an explanation that is sufficient (that is, it accounts for what is being explained, and it also rules out the possibility of some state of affairs other than that being explained). This version makes a very strong claim, and so has not been very widely accepted.

Another formulation, something that someone like St. Thomas Aquinas might defend, goes like this: "for everything that exists, there is an explanation for its existence." Notice that this version of the PSR makes a much weaker claim, namely that only the existence of every being needs explanation, and not that the truth of every true proposition needs an explanation. This version is, to me and to other philosophers, far more plausible, though it is by no means accepted universally.

I will also make a brief remark in disagreement with Yannik Ammann's answer. Under any formulation of the PSR that I have encountered, the fact that a being is necessary is an explanation of its existence. In fact, the entire point of the arguments for the existence of God of which you spoke in your question is to prove, from the premise that there are contingent beings and the premise that the existence of those beings needs an explanation, that there is a necessary being that serves as a kind of ultimate explanation, and which contains the explanation of its own existence in itself. So, whatever the other faults of the PSR may be, the possibility that it eventually runs into a "but what about God?" objection is not one of them.

*I first came across these two formulations of the PSR in Peter van Inwagen's Metaphysics.

  • So if we apply the weak PSR towards Aquinas's argument, are we suggesting that God is a necessary being and thus his existence is an explanation of his existence? And I also wanted to understand how the validity of the PSR could affect the argument that Aquinas makes because if we say that the PSR is false, then we are asserting that there are 'things' in the world that have no deterministic property towards them. Wouldn't this change the perception of the scientific theory as some things can never possibly be explained then? Shouldn't the PSR not be false then?
    – tommark
    Mar 28, 2015 at 5:42
  • To be clear, the second formulation of the PSR that I gave is not, as far as I know, actually found verbatim in Aquinas - it is only something more like what he had in mind when he defended his five ways. But yes, the cosmological argument based on this principle is meant to show that something (it may or may not be God) exists necessarily, and therefore contains within itself the explanation of its own existence. And it is also true that, if you deny this PSR, you are committed to the view that the existence of something is neither caused nor necessary (since a cause would be an explanation). Apr 1, 2015 at 1:28

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