What is the explanation for "for every fact there is an explanation"? — Corvus

Not everyone accepts the PSR, for example Hume. He challenged the PSR and argued that the ideas of cause and effect are distinct, and that we can conceive of an effect without a cause.

But suppose that for every fact there was no explanation. Then equally there would be no explanation why a fact couldn't change. For example, one day it could be a fact that "food is beneficial to humans" and the next day it could be the fact that "food is lethal to humans".

If the PSR was not valid, humans couldn't survive. But humans have survived, Therefore the PSR must be valid.

If the PSR is valid it should hold for all events whether known or unknown. — Fooloso4

The expression "all events whether known or unknown" is a contradiction in terms. It is not possible to know that there are unknown events as they are unknown. All that is known are known events.
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If PSR is restricted to what we know or observe then the reason for the star exploding is contingent upon our knowledge of it happening. — Fooloso4

The PSR is a contingent theory in the sense that it states that for every fact there must be an explanation. It doesn't state that every fact is a brute fact.

The PSR is a necessary theory in the sense that for every fact there must be an explanation.

As we don't know what we don't know, the PSR is contingent on what we know.

As regards what we know, the PSR is necessary.

For example, one day it could be a fact that "food is beneficial to humans" and the next day it could be the fact that "food is lethal to humans".

If the PSR was not valid, humans couldn't survive. But humans have survived, Therefore the PSR must be valid. — RussellA

a fact that "food is beneficial to humans" and the next day it could be the fact that "food is lethal to humans" — RussellA

I am not sure if humans survived because food is beneficial. There are some food which is lethal to some humans due to its allergic reactions causing deaths. Some humans didn't survive because of the food in that case. Therefore the premises of the reasoning is incorrect or irrelevant, which proves the PSR is a nonsense.

Therefore the premises of the reasoning is incorrect or irrelevant, which proves the PSR is not sound. — Corvus

The PSR states that for every fact there is a reason.

If the PSR was not valid, and for every fact there was no reason, then there would be no reason why facts didn't change.

Suppose one day water was beneficial to life and the next day it was lethal, one day air was beneficial to life and the next day it was lethal, one day potatoes were beneficial to life and the next day they were lethal, etc.

Are you saying that life would be able to survive in such a world?

Suppose one day water was beneficial to life and the next day it was lethal, one day air was beneficial to life and the next day it was lethal, one day potatoes were beneficial to life and the next day they were lethal, etc.

Are you saying that life would be able to survive in such a world? — RussellA

I am not sure if these reasoning prove the PSR is valid. Because there are cases, water can kill folks. Think of the cases such as flood, drowning or contaminated water which kill folks too.

Air is beneficial to folks, but the polluted air also kills folks. So they have the contradictory cases, which makes them unfit for qualifying as acceptable premises which prove the PSR true.

If the PSR was not valid, and for every fact there was no reason, then there would be no reason why facts didn't change. — RussellA

The more you try to prove the PSR is valid, the more it seems to be the case it is invalid, unsound and false due to the false premises being used in the arguments.

The expression "all events whether known or unknown" is a contradiction in terms. It is not possible to know that there are unknown events as they are unknown. — RussellA

It is not a contradiction. An event is something that happens. According to the PSR there is a reason for it happening. Our knowledge of something happening is not a requirement for it to happen. The Webb telescope has detected the earliest known galaxy, JADES-GS-z14-0, which formed about 290 million years after the Big Bang. There is a reason for it happening, whether we know it happened or not.

There is a reason for it happening, whether we know it happened or not. — Fooloso4

Philosophically, how is it possible to know something about something we don't know about?

In this particular case, that the something we don't know about has a reason.

Air is beneficial to folks, but the polluted air also kills folks. So they have the contradictory cases, which makes them unfit for qualifying as acceptable premises which prove the PSR true. — Corvus

I could generalise.

If the PSR was not valid, one day, everything that had been beneficial to life could now be lethal to life, and vice versa.

Could life survive in such a world?

In this particular case, that the something we don't know about has a reason. — RussellA

Are you arguing against the PSR?

Are you arguing against the PSR? — Fooloso4

No, I am arguing that the PSR cannot be applied to unknown events

Therefore the PSR cannot be applied to the unknown. — RussellA

If the PSR is valid it should hold for all events whether known or unknown — Fooloso4

I am arguing that it is not possible to know about something that we don't know about, including any reason for the something that we don't know anything about.

There is a reason for it happening, whether we know it happened or not. — Fooloso4

My question is, how is it possible to know the reason for something that we don't know about?

If the PSR was not valid, one day, everything that had been beneficial to life could now be lethal to life, and vice versa. — RussellA

This can happen in real life all the time, and is just a fact of life and reality. All things has positive sides, but also negative sides. It depends on what angle you are looking at the things.

For example, cars are beneficial to human life. It is fast, convenient, and essential to the business. But cars pollute the earth, contributing to major global weather changes. They can also cause people to die from the accidents ... etc. Nothing is 100% beneficial. Nothing is 100% lethal depending on how you look at them.

Could life survive in such a world? — RussellA

Of course, it can. Some life dies, but some survives. It is just a matter of the survival of the fittest.
The survival of life has nothing to do with the PSR.

No, the principle of sufficient reason says that everything that exists has a sufficient explanation of its existence. It says nothing about simplicity. Note, the more complicated of two explanations is still sufficient to explain. (I think you're conflating sufficiency with efficiency) — Clearbury

The Principle of Parsimony: the simplest explanation that accounts for all the data is the most reasonable one.
Sufficient in the PSR means that an explanation should be neither more than sufficient (i.e. it should be the simplest one), nor less than sufficient (i.e. it must account for all the data); but should be just sufficient.

The first is to insist that some things exist 'of necessity' and hope that this will somehow pass as an 'explanation' of why the thing exists. — Clearbury

Not all explanations are external to the thing explained. Here are examples of things that are explained by an internal reason, that is, out of logical necessity or inherently.
• 2+2=4 because II and II are contained inherently in IIII.
• All triangles have 3 sides by definition, or inherently.
• Same for "All bachelors are unmarried".
• Likewise, if the property of existence is contained in the definition of a thing, then its existence is explained inherently.

No, I am arguing that the PSR cannot be applied to unknown events — RussellA

Whose version of the PSR are you relying on? Where does it say in that version that the PSR does not apply to unknown events?

I am arguing that it is not possible to know about something that we don't know about, including any reason for the something that we don't know anything about. — RussellA

There is a difference between knowing what the reason is and there being a reason. According to Leibniz version, as I understand it, everything must have a reason. That reason is intrinsic to it rather than something that only exists when we know of the thing or event. We cannot say what that reason is if the thing or event is unknown, but it must have a reason whether we know it or not. If you cannot accept that then you do not accept the PSR.

in terms of metaphysics, I think grounding is a more suitable term. — Relativist

Yes that's a clearer way of putting it. It avoids the confusion of whether we speak of a reason why we know something is true versus a reason why a thing exists. So we could rephrase the PSR as: For any claim that is true, there is a sufficient reason for it to be true; and for any thing that exists, there is a sufficient ground for it to exist.

Rather: reason directs us toward truth. Induction doesn't necessarily fund truth, but it tends to lead in the proper direction. — Relativist

Yes I agree. I would add that reason is powerful enough to know its own limitations. Reason knows that induction gives inferences that are the most reasonable yet not certain.

This sounds like you're reifying logic; logic is semantics- it applies to propositions, not to reality. — Relativist

I would still say that logic has value because it reflects outcomes in reality. E.g. logic tells us that 2+2=4; and empirical demonstration shows us that if we put 2 spoons in an empty box and add another 2 spoons, we count 4 spoons in total. But suppose that, for whatever reason, we sometimes counted 3 spoons in total. This would undermine the value of using logic as a tool for finding truth.

Fallacy of misplaced concreteness (i.e. mapmaking =/= terrain). At most the PSR is, "like logic", a foundational property of reason. — 180 Proof

Sure. In other words, the content of mapmaking describes the terrain; and likewise, principles of metaphysics describe the things in fundamental reality. I accept the distinction.

The Principle of Parsimony: the simplest explanation that accounts for all the data is the most reasonable one.
Sufficient in the PSR means that an explanation should be neither more than sufficient (i.e. it should be the simplest one), nor less than sufficient (i.e. it must account for all the data); but should be just sufficient. — A Christian Philosophy

No, they're absolutely not the same principle differently expressed. Sufficient and efficient do not mean the same thing.

Take an event - P.

What the principle of sufficient reason says is that there were causes sufficient to bring P about. Causes sufficient to bring about P can be much more than is necessary. Maybe P was brought about by 100 causes or maybe 20 or maybe 1. The principle of sufficient reason says precisely nothing about that. Why? Becasue they're all SUFFICIENT to explain it. Not necessary. But sufficient. All the principle of sufficient reason rules out is one scenario and one alone: that NOTHING brought about P. That's it.

Now, it is obviously unreaonable to supose that the event had 100 causes when one would have done to expain it. But the unreasonableness of that supposition is due to the principle of parsimony, not the pricniple of sufficient reason.

Note, Tony - who posits 1billion causes for P - and Mary - who posits just one - are both respecting the principle of sufficient reason, but Tony, unlike Mary, is violating the principle of parsimony.

Not all explanations are external to the thing explained. Here are examples of things that are explained by an internal reason, that is, out of logical necessity or inherently.
• 2+2=4 because II and II are contained inherently in IIII.
• All triangles have 3 sides by definition, or inherently.
• Same for "All bachelors are unmarried".
• Likewise, if the property of existence is contained in the definition of a thing, then its existence is explained inherently. — A Christian Philosophy

All you're doing there is drawing attention to some claims whose truth is explained by appealing to truths of reason. It has nothing to do with existence being contained in the definition of a thing.

It is a truth of reason that all contradictions are false and thus correspond to nothing in reality. The notion of a married bachelor, given the conventional meanings of those terms, contains a contradiction. And thus by appeal to the law of non-contradiction we can 'explain' why there are no married bachelors.

But the principle of sufficient reason - which says that everything has an explanation - must now be applied to the law of non-contradiction. What explains why it is true?

No good appealing to the fact it's obviously true. For that is no explanation. And no good saying 'it is a necessary truth' for that explains nothing either.

If you think the basic laws of reason - and again, it is those that 'explain' why there are no 4 sided triangles or married bachelors - do not require explanation, then you're rejecting the PSR, for you'd now be saying that it is only things 'other than' the basic laws of reason that need explanation.

Since the PSR states that every thing must have a sufficient reason, no exception, then both 2) and 3) would be deniers of the PSR.

We cannot say what that reason is if the thing or event is unknown, but it must have a reason whether we know it or not. — Fooloso4

For Leibniz, God knows all events whether known or unknown by humans.

Can you justify your statement above, in that if an event is unknown to humans then we as humans know that it must have a reason, even if we as humans don't know what the particular reason is.

Is your argument based on the existence of a God?

Since the PSR states that every thing must have a sufficient reason, no exception, then both 2) and 3) would be deniers of the PSR — A Christian Philosophy

You defend the PSR, in that for any thing that exists or is true there is sufficient reason.

Principle of Sufficient Reason (PSR): For any thing that exists or is true, there is a sufficient reason for it to exist or to be true.............We then defend its validity as a first principle — A Christian Philosophy

You also give the examples of things that don't have a sufficient reason, but rather logical necessity, such as "All bachelors are unmarried".

Not all explanations are external to the thing explained. Here are examples of things that are explained by an internal reason, that is, out of logical necessity or inherently. — A Christian Philosophy

Your position seems to fit in with item 2).

For Leibniz, God knows all events whether known or unknown by humans. — RussellA

Up until this point you have been treating unknown as unknown to us. If God knows then even if we do not there is still a reason for all events, reasons known to God. The reason for something is not contingent on our knowing the reason.

Is your argument based on the existence of a God? — RussellA

My argument is that if you accept the PRS then you must accept that there is a reason for everything whether that reason is known to us or not. One might, of course, object along the lines of our not knowing that there is a God who knows all things.

My argument is that if you accept the PRS then you must accept that there is a reason for everything whether that reason is known to us or not — Fooloso4

You propose a formulation of the PSR that states that for everything, whether known or unknown, there must be a reason.

You must feel that there is a justification for this particular formulation.

But do you know of any argument justifying that there must be a reason for things not even known about?

If not, then why accept this formulation?

You propose a formulation of the PSR — RussellA

I don't propose it. I cite it.

You must feel that there is a justification for this particular formulation. — RussellA

Prior to the question of whether one agrees or disagrees is the question of what the principle is. The principle is not based on our ability to know the reason, but rather states that there must be a reason.

I do not know that there is a reason or that there is not a reason for everything

If the PSR is true, then we know about everything in the universe.
We don't know about everything in the universe.
Therefore the PSR is not true.

P -> Q
~Q
=======
~P (MT)

Isn't reason a product of human mind? Reasons don't exist out there in the external world. There are only matter, energy and changes in the world. Reason is an operation of human mind seeking for the causal explanations on the existence and changes. — Corvus

As described in the OP, reason in the context of epistemology can be interpreted as explanation or justification for a claim be true; and reason in the context of metaphysics can be interpreted as cause or grounding for a thing existing.

Even if the world was only physical, there are still causes or grounds for the existence of particular physical things. E.g. The egg is caused by a chicken, etc.

For the proper operations of the inductive reasoning, human observations do need the data to draw the reasoning for the conclusions. Therefore there are many events and existence which have the reasons, and many are unknown due to lack of the data. — Corvus

I agree. The PSR would say that everything that exists has a sufficient reason (or cause or grounding) even if some of these reasons are not known to us.

Something does not exist because you posit its existence as necessary. — Fooloso4

I agree, but in this case it is not arbitrary. The existence of a being whose existence is an essential property is deduced directly from the PSR. Since the PSR demands a reason for everything that exists, and since external reasons (i.e. causes) cannot sufficiently explain everything because we run into an infinite regress, then it is necessary to have an internal reason, that is, a being whose existence is an essential property.

This thing whose existence you posit designs the laws of nature that cannot be explained naturally. — Fooloso4

What else could it possibly be? We could entertain that the laws of nature are caused by prior laws, but this only pushes the problem one step back. To avoid the risk of infinite regress, the fundamental laws must be explained by something that requires an explanation but not a cause.

The concept of "necessary" applies to logic: e.g. in a valid deductive argument, the conclusion follows necessarily from the premises. — Relativist

Sure, but in the same way, necessity also applies to things with essential properties. E.g. "3 sides" is an essential property of a triangle. Thus, if a thing is a triangle, it logically or necessarily follows that it has 3 sides. Therefore, we can call essential properties "necessary properties".

Why think "necessary" is an ontological (de re) property of any being? [...] I suggest that any first cause (including a natural one) would exist necessarily: it exists autonomously, and without a cause that could account for its contingent existence. — Relativist

Would this mean that this type of first cause exists without a reason, and thus would violate the PSR? Whereas my first cause, the being whose existence is an essential property, has a sufficient reason to exist: it is an internal reason, that is, its existence is explained logically or inherently.

I don't propose it. I cite it. — Fooloso4

There are different formulations of the PSR. You cite one version of it. See SEP - Principle of Sufficient Reason.
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The principle is not based on our ability to know the reason, but rather states that there must be a reason. I do not know that there is a reason or that there is not a reason for everything — Fooloso4

A principle that cannot be justified shouldn't be used.