The Principle of Sufficient Reason is a powerful and controversial philosophical principle stipulating that everything must have a reason or cause. This simple demand for thoroughgoing intelligibility yields some of the boldest and most challenging theses in the history of metaphysics and epistemology. In this entry we begin with explaining the Principle, and then turn to the history of the debates around it.
I think it would be a shame if a discussion over PSR was embedded deep in some other thread somewhere. So here’s hoping Erik and KN will take up any discussion around it here in this thread. (Yes, you’re not just talking to each other.)
But I’ll start by taking the first shot as is my right having created the OP. 🙂 I think there’s a more fundamental disagreement between Erik and KN than the PSR, and that would be over the very possibility of metaphysics itself. Or I could be all wet!
Please discuss. Thank you.
I think it would further discussion if the principle were put more clearly. First of all “reason or cause” is a little bit of a problem (if “reason” isn’t just another term for “cause.” And second what is meant by “everything.”
“Every event has a cause,” I sort of have a sense of. “Everything has a cause or reason,” I find kind of bewilderingly broad.
As defined above, I believe the PSR to be false. However, I do agree with KN’s view. That is, I take it to be a methodological principle. That is to say, we should be looking for reasons and causes.
Neil, why would you take something you believe to be false and employ it as a methodological principle?
Without actually telling you what you believe, let me instead offer up my opinion as to how things appear to me.
You believe it to be false, but you act as if it is true.
Isn’t that what you’ve just said?
What does it mean to be rational, or to be a rational being? Is it rational to believe that the PSR is false and yet act as if it is true?
I see it as false as a principle (there appear to be violations in QM), yet in practice it applies most of the times that we want to use it.
If it is the case that “in practice it [the PSR] applies most of the times that we want to use it,” what reason is given for believing it is false? Does quantum mechanics resort to “brute facts” in lieu of explanations? What are the facts of QM that need no explanation?
There appear to be uncaused events in QM.
It’s not a question of “need no explanation”, for need is a human emotional response. If you accept “uncaused events happen” as sufficient explanation, then fair enough. But in that case, what counts as “sufficient reason” is subjective.
Neil, what sort of logic gets us from the premise that “there appear to be uncaused events in QM” to the conclusion that “therefore, the PSR is false”?
Or how does one even traverse from the premise that “there appear to be uncaused events in QM” to the conclusion “therefore, uncaused events happen”?
Do try not to beg the question.
Interesting. iirc Feser has something to say about PSR in his Scholastic Metaphysics: A Contemporary Introduction. I’ll try to dig that up.
But of course I think the PSR is true! Why would anyone think otherwise?
It’s simply that the PSR is a prescriptive claim, not a descriptive one. But why on earth would anything think that only descriptive claims have truth-value?
Good post Mung. Do we need logical absolutes, or exploitable regularity?
God violates the PSR, no?
There’s also this article about the PSR from Michael Della Rocca http://quod.lib.umich.edu/p/phimp/3521354.0010.007 also reviewed by Edward Feser http://edwardfeser.blogspot.com/2014/10/della-rocca-on-psr.html
The article starts off with explicability arguments – we inevitably use explicability arguments and cannot do without them, if we are to be considered rational or sensible. This by itself does not commit us to the full-blown version of the PSR, but it would/should if we were consistent. I guess this is the gist of it. And I agree.
@Mung
According to this article http://www.arts.cornell.edu/Knight_Institute/publicationsprizes/discoveries/discoveriesspring2011/004.%20O%27CONNELL.pdf Abelard’s heresy was of a whole different nature.
Blasphemy against the Trinity, in other words.
Try starting page 105. It’s nonsense, in my view.
Why do practicing Christian scientists do it? They may not believe naturalism is true, but they do assume it to be true as far as a methodological principle.
I think Abelard’s dilemma resulted from the fact that God was thought to be so intelligent, powerful and good that He would never do anything without the best reasons. That seems to put him at the mercy of the reasons, thus reducing his power.
It is important to note the “must” in the subsequent definition provided by mung above; it’s not supposed to be a contingent truth, but a necessary one. That’s the rub. If one does not start with the view that there is some entity that is all powerful, etc., one does not end in Abelard’s predicament, and the PSR doesn’t seem to follow from something else–God’s goodness and power. (Admittedly, one’s beheading comes much more quickly for those advancing such an argument.)
So consider the “blasphemy” committed by Abelard when he took this view (ignoring, for a moment, his more famous escapades): he dared to think that anything worthy of worship could only do what was best. That seems to require something like a PSR applying to God. His actions must be explicable–why? because everything is.
But start with no idea that there’s a God (i.e. join us fools who sayeth in our hearts that there is no God) and say why there must be a “reason for everything.” Even if, in every single case we’ve always found that there IS a reason for each thing we’ve investigated–why MUST there be? We can’t get the necessity, the “must” without bringing in some God who’s too nice to confuse us.
What I’m saying here (not very eloquently, I’m afraid), is that we have a circle.
As Neil says, QM is sometimes used as a counter-example.
But what if we take the multiverse interpretation? Then the explanation for probabilities and indeterminism involves our limited viewpoint. We can only deal with one universe (or at least, each version of one of us can only deal with one universe at a time). But step back to the multiverse perspective and then all the possibilities occur; no need to worry about an SR for one of them only.
Now Tegmark steps even further back, factoring in eternal inflation and some imagination, and says all universes with (roughly) a mathematically computable structure must exist. Given multiverses from QM and inflation, the further arguments for this are logical, not empirical, as I recall. So they are not contingent. So we have an SR which produces all possibilities, including what happens in our particular universe.
Done.
My contention is that it’s both. The PSR is prescribed because it works and it works because intelligibility is the very nature of reality. The only meaningful way to discuss such reality is in terms of explicability, i.e. PSR. It so happens that putting things in terms of explicability comes naturally to us, which means it must be the nature of the self-same reality.
Nothing is really gained by asserting that a useful rule of thumb is a principle of reality. You are simply assuming your conclusion.
Case in point: quantum theory. There’s a lot of woo associated with quantum this and that, but there is an underlying woo-free lesson to be learned.
Principles of reality are better treated as guidelines than as rules. You have to go where the evidence leads rather than where the principles of reality demand.
Let’s suppose that Abelard’s error consists in arguing that God must create the best of all possible worlds, and if not, there must be some reason for it why not. The crux of the problem, in my view, lies not with the PSR, but with the univocity of “best”. Abelard wants the best for creatures, not for God. These are not the same kind of “best”. Aquinas had elaborated a doctrine of analogy that highlights the pitfalls of univocal usage of divine attributes.
Another not terribly impressive demonstration from the ‘Just give me some proofs’ guy. Bruce, based on these posts I will speculate that no Intro to Logic class has factored in this ‘trained philosopher’s’ past.
Then you can surely disprove my statement. Maybe you fare better than KN.
Oh Erik. Tsk tsk. The fact that some proof of X fails doesn’t entail that the contrary of X can be proved. Better re-read your Aristotle!
Then my statement stands. Don’t whine about it.
Wrong again. Statements (like ‘there are penguins living in mansions on Rigel 3’) don’t ‘stand’ because they aren’t provably false. The burden is on the proponent of these statements to provide support for them. Your proofs are no good AND your understanding of warrant is also no good.
BTW, I think KN would ‘fare better’ in his discussions with you if he didn’t always assume that you have the slightest idea of what he’s talking about. I know this isn’t very nice to say, but it sometimes reminds of what it would be like if Prof. Irwin Corey had a prolonged conversation with Bullwinkle the Moose.
I view myself as a sort of baseball fan viewing the discussion from the stands.
So I now feel like I’ve been hit by a foul ball.
By your own principle, since you are not bearing the burden of proving anything, then whatever you are saying here either doesn’t stand or is false (or both) – and my responsibility in this matter is limited to just stating it.
I will ignore your baits in the future.
And you are assuming that the principle is a mere rule of thumb – based on what? Does it have exceptions? Are there cases where it doesn’t work? Is there another rule or principle that overrides it?
walto,
I think Abelard’s dilemma resulted from the fact that God was thought to be so intelligent, powerful and good that He would never do anything without the best reasons. That seems to put him at the mercy of the reasons, thus reducing his power.
I think the reasoning is that God acting without the “best reasons” is contrary to His Nature. God acting contrary to His Nature is logically impossible . Since even a omnipotent God cannot preform the logically impossible, there is no reduction of power.
Erik, You can, of course, ignore my posts, and, as you have obviously done in the past, treat attempts to enlighten you about how logic works as “baiting.” But your last post is also wrong–or to be more accurate, if you want it, you can have it.
You claim you have given a proof of some proposition–Call it ‘X’
It is pointed out that your proof of X is no good.
You then claim that if this were true then someone should be able to prove not-X
It is then pointed out that that claim too involves an invalid argument.
Note that those corrections are based on LOGICAL (not empirical) principles. (In fact, there’s nothing beyond Aristotle there.)
You now fall back on the (absurd) claim that in any case someone can’t meet a burden of support for some proposition X, the burden must shift to whoever denies X, that, indeed, stating X constitutes the entire responsibility for anybody to assert X.
That, however, is simply to deny that one ever has the burden for supporting any cuckoo statement one can make up (such as “there are penguins living in mansions on Rigel 3”)–or that any such burden is met simply by asserting it as a fact.
Now, of course, it is perfectly possible to set up epistemic principles (an “ethics of belief”) which takes a bald assertion as sufficient support for anyone who says anything. There would be nothing contradictory about such a system. But it has consequences. It means, in the instant case for example, that nobody has any more reason to believe your contention that the PSR is true than to believe that there are penguins living in mansions on Rigel 3.
Good for you!
As you are hell-bent on ignoring any instruction in logic, I fear that your posts will continue to be riddled with fallacies. But–to each his own.
I readily accept the principle:
Everything has a pseudo-explanation.
The world is full of pseudo-explanations.
newton,
Yes, that sounds right to me. And he got in trouble for suggesting this “limitation” to God’s power!
Leibniz straightened all that out, however. (He was very smart.)
@walto
Let’s apply your claims to specific examples in this thread, so you can follow for yourself what you are saying here.
Example from me: “The PSR is prescribed because it works and it works because intelligibility is the very nature of reality. The only meaningful way to discuss such reality is in terms of explicability, i.e. PSR. It so happens that putting things in terms of explicability comes naturally to us, which means it must be the nature of the self-same reality.”
So, you countered, “Another not terribly impressive demonstration from the ‘Just give me some proofs’ guy. Bruce, based on these posts I will speculate that no Intro to Logic class has factored in this ‘trained philosopher’s’ past.”
Note that this does not point out how my proof is no good. You are here making the claim that you find my statement ridiculous, but you are not taking the appropriate responsibility of showing why you think so.
This is what I call baiting and this is the attitude that you have consistently maintained. It’s an attitude that I don’t have to have anything to do with.
So, in response to your counter, I said, “Then you can surely disprove my statement.”
Clearly, I did not ask you to prove not-X. I asked you to disprove X. You didn’t even attempt it. Instead you are eagerly misreading the situation.
Clarify your own misunderstandings.
Over and out.
You conveniently forgot to quote the relevant pat of my post.
Reasons or explanations don’t exist in isolation. They exist only in relation to the person seeking an explanation and have some sort of utility to that person.
I think the PSR is pretty much valid except for the question of how the universe came into existence, where all our categories fail.
I’m curious why there even needs to be a PSR. Why does it need to be stated or affirmed? Is it a stepping-stone in rigorous thinking to a more profound field of thought?
That is why I asked what I did. When you start with a principle, you presumably derive things from the principle. That is antithetical to science, and leads down blind alleys. You can derive conjectures and hypotheses from principles, but you have to be prepared for contrary results.
You mean the next post? If you think your point is clear enough as stated, then forget about it. Otherwise I would have asked for some elaboration on what your argument from quantum woo entails.
To me, the very nature of reality is rocks, weeds, mosquitos and other annoying things.
But to each his own.
Quantum theory reminds us that nature isn’t ruled by axioms and principles.
Quantum theory is pretty much unintelligible without a few years of graduate level math, but it is clear even to a layman that quantum theory and general relativity violate our intuitive expectations. You cannot predict the findings of science from principles.
Hence the shambles created by Barry Arrington when he tried to disprove quantum indeterminacy by appeal to axiomatic reasoning.
OK, I take this to be a positive step and I congratulate you on taking an interest in why something you said might not be right. I will, therefore, clarify some misunderstandings. They are actually your own, however.
You ask me what is wrong with this argument:
{I note that I have begun your quote there because what precedes it :
“intelligibility is the very nature of reality”
is really a conclusion. At any rate you give no support for it, and would beg the question to put it as a first premise in any argument for PSR.}
So, what we have is this:
Putting things in terms of explicability comes natural to us.
Therefore, everything must be explicable.
I think it should be obvious that there is nothing much that can be said on behalf of that “argument.” It has roughly the same form as
Breathing in and out comes natural to us.
Therefore, everything requires breath.
I disagree profoundly. I happen to be one of those people to whom primary schools physics made hardly any sense, but as soon as quantum physics was introduced, I knew immediately what was going on and regretted all the years wasted on Newtonianism.
A specific example would be helpful. What logical axioms or intuitions does QM disprove? E.g. does the double slit experiment disprove (or call to doubt) the law of excluded middle? If yes, how?
I think there’s a deep problem here. Consider this related way of putting the point:
(1) We do experience the world as intelligible-to-us;
(2) If the world had no intrinsically intelligible character, then (1) would be unintelligible;
(3) So the world must have some intrinsically intelligible character.
But notice that the move from (2) to (3) in fact presupposes the principle of sufficient reason — which means that (3) cannot used to justify the PSR without begging the question.
As I see it, the PSR is a constitutive norm of inquiry — it says what one must do in order to be undertaking the social practice of inquiring at all.
Keith deRose on the PSR and the existence of God:
— from “Why Take a Stance on God? Gary Gutting Interviews Keith DeRose“
When we say that something exists or comes into existence its taken for granted that this ‘something’ is within universe. Neither of these notions can be applied to the universe itself.. I think saying the universe exists or came into existence is nonsensical in a way because we’re lumping it together with objects within the universe. The way our minds organize reality just don’t help with questions like this. That’s why so many people are willing to answer the question of how the universe got here with an answer that is essentially ” a guy made it” ……so the PSR is a great heuristic…and that’s it.
Quantum theory doesn’t disaprove anything. I cite as a warning not to reason from principals. Or at least to be aware that intuition is not a good guide to making new science. We can describe things with great precision without being able to say what it means to be a thing.
We can predict phenomena without being able to fully characterize causation. We don’t know what time is or whether it is an illusion. Yet it would seem that causation requires a conventional kind of time.
First, I disagree with the way you have reduced my statement. You intently design flaws into it, but let’s begin with your misreformulation anyway.
The last thing first.
Breathing in and out comes natural to us.
Therefore, everything requires breath.
Obviously there are things that don’t require breathing (at least not in the same way as we do), so this is not the form of my argument. My complete statement is more like a cumulative case. Here it is once more:
The PSR is prescribed because it works and it works because intelligibility is the very nature of reality. <– This is a statement of my thesis and what it entails, an assertion if you like. The latter part is a fundamental conclusion and the former an implication to it. It was meant as an introduction for KN.
The only meaningful way to discuss such reality is in terms of explicability, i.e. PSR. <– Here I mean that if reality itself is intelligible, then talking about it in terms of explicability is necessarily the right and true (and workable) way of handling it. For a more complete treatment about how consistent explicability entails PSR, see Della Rocca’s article.
It so happens that putting things in terms of explicability comes naturally to us, which means it must be the nature of the self-same reality. <– Here I presuppose that we (rational humans) are part of reality. Given that we are part of reality, then the things we have/do reflect the nature of (part of) reality, right? (Sidenote: That “reality” has an element of human subjectivity to it is a standard presupposition in classical metaphysics.) Still, whatever we do is the nature of reality not only insofar as it comes naturally to us, but also insofar as it works to clarify the nature of reality, making it intelligible. We care a lot about how things work, right? So, we care about intelligibility, because reality works by means of it.
The nature of reality is properly that which we have comprehended, that which we have made intelligible to ourselves. The part which we have not comprehended (yet), if we assert anything about it, it is an assertion from ignorance.
To put it another way, when we first perceive something, anything, we don’t always know what it is. After taking a closer look and thinking it through properly, it becomes intelligible to us and then we say we know what it really is. This makes the PSR essential to reality by the very definitions of “reality” and “intelligibility”.
Like Newtonian laws, explicability works well in ordinary experience. It fails at the beginning of things and in very small things. It’s a rule of thumb.
Actually, we experience the world as alternately intelligible and unintelligible, so the rest doesn’t follow. What follows is that unintelligibility doesn’t work and doesn’t clarify the nature of reality to us so that we could say anything certain about it, while intelligibility does.
If you talk in unintelligible terms and/or about that which is unintelligible, you literally don’t know what you are talking about, whereas inasmuch as you talk in intelligible terms about that which is intelligible, you can be sure it’s true to reality.
Correct, but it doesn’t stop there. It’s not just an arbitrary social norm suggesting what we should do. Things actually work when we observe it in a principled manner. So it’s properly a true principle, not a suggestion or a rule of thumb.