is p valid or invalid?

No. An argument is valid if the conclusion necessarily follows, as a matter of deduction, from the premises. If p then q is not an argument.

"If P then Q" is just a conditional operator, there is nothing not valid about it. I have never heard anyone claim that "if p then q" is not valid. Will you be claiming that p is "not valid" as well. Are you sure that you understand validity?

If A implies B then the falsity of B implies the falsity of A by modus tollens. Whereas the proposition "I do not think therefore I do not exist" must be false if indeed I do not think (and yet exist), the proposition "I think, therefore I exist" needn't be false in the event that I do not think. In that case, the falsity of the proposition "I do not think therefore I do not exist" does not imply the falsity of "I think, therefore I exist."

Corvus, perhaps you were thinking that if I did not think, I would not know that I existed; in that case, it would appear that my existing could not be decoupled from my thinking. While it is certainly true that if I weren't thinking, I would not know I existed, there is surely a possibility that I do still exist (even if I am not thinking), as Banno stated.

But I don't think or I think, therefore I do not exist is false — Corvus

Corvus, is the correct interpretation here that: "I don't think...or it is false that I think therefore I do not exist." (1).

Or is the correct interpretation here: "it is false that "whether I think or I don't think I do not exist." (2).

And since I really do think the argument is valid, I would ask you again whether the conclusion from my argument sounds right to you?

Any 1 line argument is invalid because it is not an argument! Even "If P Then Q" is invalid according to the program you referenced.

But Banno, of course that argument is invalid. That argument is only 1 step. My argument is three steps. I should be quite surprised to find that the argument I laid out is invalid.

Hmm, I am surprised to see that the argument is invalid and would very much like to know why it is invalid. It seemed to me to be quite a good formal argument.

Very well Banno, I shall look to see if Socrates is around. He is usually most amenable to having a discussion.

Banno, where are you going? I am quite sure we were just now on the verge of a breakthrough. Are we to turn away from the discussion at this critical juncture?

Still, I would like your opinion on the conclusion, is it acceptable or not?

Would you endorse the above conclusion, or reject it? I mean just the last line, does it seem agreeable to you?

Splendid!

Now consider this argument:

If not (if I think, then I exist), then (if I don't exist, then possibly I think).
Not (If I think, then I exist).
Therefore, if I don't exist, then possibly I think.

I do not know what your emoji means.

I just mean formally speaking, let's not worry about what our premises are for now.

It's a secret. So what do you say, does that argument look agreeable?

Here is a more formal statement of an argument:

(1) if not (p then q), then (if not-q then possibly p).
(2) not-(p then q).
(3) Therefore, If not-q then possibly p.

Can we all agree with the first conditional, or would someone object to it (and if so what is the objection).

(1) If I think, then I exist.
(2) I think.
(3) Therefore, I exist.

Premise one is not explicitly stated in the cogito argument (at least I don't think it is), but surely it is implied.

The formal structure of this argument is:

(1) If p, then q.
(2) p.
(3) Therefore q.

It is a valid argument.

Or have I missed the boat on this one?

I am reminded of the debate between scientific realism and anti-realism. This is a debate that may have implications for both naturalists and supernaturalists and one that both can engage.

Nevertheless, couldn't one maintain that God is "in" the world in a non-spatial sense in addition to having a causal or sustenance role? I do not see how that would be problematic or even controversial for most theists.

I am less concerned whether someone else' argument is fallacious or ill-reasoned, of greater concern to me is that someone (including myself) can understand and represent the argument stated. If they can't do that, or if I can't do that about someone else's argument, then that is a sign of not comprehending. Further, there can be no "meeting of the minds" if the others' argument is not stated and represented as that individual has stated it. In other words, social reason collapses if no attempt is made to understand (even a fallacious reasoner).

So in summary, I would give less prominence to the "reasoning" abilities of an individual (because that may assume a criteria of knowledge or rationality to which the interlocutor may not agree), and greater prominence to their ability to re-assert and understand another's view. If someone won't do that then there is simply no discussion to be had.

We also must distinguish between an argument's soundness and its validity. An argument can be valid without being sound. If so, that's not a reasoning error, that just means an assumption is wrong. I am not sure that someone can be "reasoned" out of an assumption.

Unless they do not accept the law of noncontradiction

I think it is important to understand the "other side " of an argument. If someone can't do that , that's a sign they do not have understanding of the "other side." And in that case, they can't reasonably object to it. Someone with understanding of both sides is in a much better position to adjudicate.

I think the proper theist response is not to try prove that God is something that exists, but is the ground or cause of anything that exists. That is not an empirical argument.

So, for those who are supernaturalists in this forum: what phenomena do you believe cannot be sufficiently explained naturalistically? — Bob Ross


Phenomena are appearances - that is the origination of the word. And from a non-theistic philosophical perspective, something this doesn’t account for is the nature of the being to whom phenomena appear. — Wayfarer

Wayfarer, looks like your answer to Bob Ross regarding the phenomena that are not accounted for on a naturalistic account is just this: everything.

I find that just a bit humorous.

If reason functions as a social product (I think Habermas says something like that (perhaps Fichte to some extent too)) then it may be that reason can be instilled into this individual viz. interaction with other rational individuals. In that case, patiently correcting someone for their logical infelicities may be best. Also, logic classes help. Lastly, I think epistemic humility is important.

Also, I assume this post is not about me, otherwise...irony!

You might be interested to read Shamik Dasgupta, especially what he has to say on "Absolute Velocity" -- http://shamik.net/papers/dasgupta%20symmetry%20as%20an%20epistemic%20notion.pdf

I think you will also find discussion of the "Invariance Principle" as it pertains to physics interesting and perhaps quite agreeable. -- I think Nozick talks about it to some extent.

Let me sum up my point about a vicious infinite regress. In a YouTube video, Dr. Craig says that without creation, God is timeless and temporal after it. On the other and, classical theists believe that God is absolutely simple with no parts of any kind. And potentials are metaphysical parts. So, if God is purely actual, there's no potential in him. But Dr. Craig implies that God is metaphysical parts when he, Craig, says that God went from being possibly in time to being actually in it. Any object with potential is a composed object. And each composed object needs cause to put the parts together. So you end up with infinitely many composers but no composed object. — BillMcEnaney

Time aside, would it not be the case that God as pure actuality is "in" the universe in only a "potential" way prior to creation, and in a "non-potential" way once creation has occurred? How do you make sense of that? (Note: I guess it would not have been a problem for Aquinas if Aquinas thought the universe was eternal/infinite).

Perhaps it is a mischaracterization to describe the state of God outside creation as "potentially" in time? In wonderer1's quote, Dr. Craig does not use that term.

If creation does not yet exist, can God bear any relation to it viz. potentiality? But if not, then God needn't be a composite of potentiality and actuality and there is not infinite backpedaling.

Hi,

I would begin by questioning the soundness of accepting a principle such as the principle of parsimony. Why would a simpler theory be prima facie preferable? What virtues does it espouse over a more complex theory? It may be easier to understand a simpler theory, so maybe there are practical reasons to choose it; but in terms of the veracity of a theory, I don't see why a simpler one is of greater import.

Secondly, I do think there are some phenomena that are not accounted for by the naturalistic thesis. What I have in mind are much the things you would expect me to say as a supernaturalist: places like Heaven and Hell, entities such as angels and demons, but also events such as the miracle of Fatima, and other miracles that I believe in as a Christian, such as the resurrection. I realize that the occurrence of such supernatural phenomena may provoke incredulity from a naturalist. Belief in these things is not only through testimony, but also an article of faith for me.

Time has nothing to do with it though, so the principle of plenitude is not doing any work in your argument. Not to mention, you are describing Aquinas' Second Way: if everything is contingent and contingent things require a cause, then there would be nothing because nothing would cause all the contingent things (even if there were an infinite number of them); that is approximately the Second Way.

Oh I see, so then you are saying that there would have been nothing today if everything were contingent because there would have been nothing before any contingent things and that that nothing would have prevented all the contingent things from existing entirely. Do I have that right?

Therefore the proposition "all things are contingent is incoherent", and there is necessary being. — Metaphysician Undercover

Right. I am asking you: "if everything is contingent, would there have been nothing today because there would have been nothing after all contingent things existed, or because there would have been nothing before all the contingent things began to exist?"

Since "all being is contingent being" implies an infinite regress of causation, therefore an infinite amount of time prior to now, nothing would have already occurred, prior to now, by the principle of plenitude — Metaphysician Undercover

And would you say the nothing that occurred happened after all the contingent things passed away, or would you say the nothing occurred before the contingent things were generated?

prior to now — Metaphysician Undercover

That is the crux of the matter. The problem for the principle of plenitude is not when nothing is prior to now; the principle handles that objection well. The problem is when nothing will occur (or may occur) after now. That's the objection I am stating. Do you see why I think it is a problem for the argument you stated?

By the nature of "contingent being", it is shown that it is impossible that "all being is contingent" by Aquinas' argument. Therefore the hypothesis "everything is contingent only" is rendered incoherent. — Metaphysician Undercover

But that is the problem isn't it; Aquinas' argument as you have stated it does not go through if there could be nothing posterior to "now." If there could be nothing posterior to "now" it could be the case that everything is merely contingent.

I don't see how the necessity of the premise (2) "something existed in the past" is supported, when (1) explicitly says there could have been nothing in the past. That is the point of Aquinas' layout, it shows how (2) which contradicts (1), rendering the primary hypothesis "everything is contingent", as incoherent, is derived. — Metaphysician Undercover

But (1) does not explicitly say there could have been nothing in the past; it says "if everything is contingent, then there could have been nothing in the past." It's a conditional statement, that is it. And that is basically what Aquinas is doing too, he is entertaining, in the same way a conditional does, the possibility that "everything is contingent."

There is no need for Aquinas to elaborate or clarify his use of "now" because he does not use it to distinguish between past and future. You made that distinction in your argument, so this left you open to that criticism. — Metaphysician Undercover

But the original argument I formulated (1-4) does not make use of the past or future, rather it only discusses the present, so again I am not sure how my use of "now" is different than Aquinas'.

you are just carrying on with a proposed possibility which has already been proven to actually be impossible by being incoherent. — Metaphysician Undercover

How is the proposed hypothetical possibility impossible by being incoherent?

I really do not think you will make any progress in this direction. — Metaphysician Undercover

I did not see where the objection was in these two paragraphs.

This does not resolve the issue with "now". — Metaphysician Undercover

Okay fine, let's forget about "now" and say instead that any moment in the past must have been. I will reformulate my argument:

1. If everything is contingent, then there could have been nothing in the past.
2. But there couldn't have been nothing in the past, something having already existed in the past.
3. Therefore (by modus tollens) it must be false that everything is contingent.
4. Therefore there must be a necessary being.

Although I really do think Aquinas meant "now" as I do, in the colloquial sense, not in the technical sense you have described. Otherwise, wouldn't the objection you stated concerning "now" be a problem for Aquinas too?

You said you would start the sim as a zygote. I am asking: what is the difference between this zygote and a zygote in reality? Or is the zygote you are postulating a mere simulation of a zygote? If so, that seems problematic.

What is the difference between the simulation and reality if you are constructing "simulated people" based on the same historical states that result in non-simulated people? If the physicalness of both systems is identical in all respects, what is the difference?

Picture 'reality' R0 as the trunk of a tree. It has 9 boughs (S1-S9) coming out of it, the simulations being run on R. Each of those has 10 branches, labeled S10-S99. Those each in turn have 10 sticks (next level simulations (S100-S999), Then the twigs (S1000-S9999) and the leaves (S10000-S99999). Every one of those simulation has say 10 billion people in it, so a given person is likely to be simulated (all except the ones in R0), and most of those (90%) find themselves in the leaves — noAxioms

Ah, I see, thanks for explaining!

Regarding your objection re: physicalism. The problem with conscious people within/part of a simulation has to do, in my opinion, with the historical necessities of consciousness. That is to say a simulated person does not have the requisite history to be conscious. We need not evoke anything supernatural in this description of consciousness, we can keep everything purely physical. All we're saying is that someone that is conscious must be alive, and someone alive must come from someone else who is alive, that is, from the womb.

You are proposing that the sequence of contingent beings has a beginning, in order to avoid the infinite time prior to now, and the principle of plenitude, which would indicate that in that infinite time there would be a time of nothing. But contingent beings must have a cause. If there is a first contingent being, one which is prior to all other contingent beings, it cannot have a contingent being as its cause, then its cause is necessary, and this is necessary being as distinct from contingent being. — Metaphysician Undercover

Not exactly, what I am proposing is this: First, let's assume that all beings are contingent only; that is, that there are no necessary beings. On that assumption, whether the principle of plenitude is applicable or not, but especially when it is applicable, the problem I articulated is salient. The problem is not that there are contingents posterior to "now." The problem is that there will be or may be nothing posterior to "now," that is, if we are still operating on the hypothetical assumption that everything is contingent only.

That is why I am forwarding the argument that I forwarded. But you mentioned an objection to that argument:

This is sort of like Aristotle's law of identity. Whatever exists [now] must be what it is, and not something else. This is expressed as the following necessity: "A thing is the same as itself". Notice though, that this relates to a thing's essence, what the thing is, which cannot be other than the thing's essence, what the thing is. But this principle has not been extended to a thing's existence, as you propose, and I believe it cannot be, for the following reason. — Metaphysician Undercover

I am not sure if the law of identity can be extended to a thing's existence either. Fortunately, I am not appealing to the law of identity; rather, I am appealing to the law of noncontradiction. In particular, I am appealing to what Aristotle says in De Interpretatione. The first sentence of Part 9 especially: "In the case of that which is or which has taken place, propositions, whether positive or negative, must be true or false." In other words, it must be true or false that something exists now, it cannot be both true and false.

And I would like to address the further objection you described concerning "now" --

In fact, the "now" changes as we speak. Therefore we cannot make the proposed statement, "it is necessary that what exists now exists now", because time has past between the first "now" and the second "now" such that they refer to different times which accordingly have different existents. — Metaphysician Undercover

I am not using now in a purely indexical sense. By "now" I mean this exact present moment. Which, in a few seconds will have become "then." Still, something must have existed in "that" moment.