When I read this it feels like it'd go the same with objects... we cannot say objects, and so they are ineffable. — Moliere

So what is it about activity that makes it different from objects? Why can't we just note that activity, experience, and words aren't the same, but we can talk about them? — Moliere

"Some things you have to learn on your own" looks like it is about an ineffable entity we might call "knowing how to ride a bike", but there is no difference between "knowing how to ride a bike" and "riding a bike"; we don't have two things here, one being bike riding and the other being knowing how to ride a bike. — Banno

Or, suppose we had a list of the instructions for riding a bike, to whatever detail we desire. Would we then know how to ride a bike? Well, no. So what is missing? Just, and only, the riding of the bike. But that's not something it makes sense to add to the list! — Banno

What is there that cannot be said? — Banno

"...it hardly conveys the full experience" - of course not! That has to be experienced! — Banno

But as suggested to Frank, that just means that it is not something to be said, but something to be done. — Banno

We cannot impose on the ball that it cannot not be red, just because our reasoning says so, because our reasoning might be wrong. — Metaphysician Undercover

I would say these are not an example of "opposition" but "negation". A dynamic between the "necessary" and "possibile" would be more of an oppositional relation. — Merkwurdichliebe

It is not impossible to imagine any object being red or not being red. So even if all examples of a certain kind of object were red, it does not follow that a non-red object of that kind could not turn up. — Janus

Even if (although we could never know it) all objects of a certain kind have been, are and will be red it does not seem to follow that it would be necessary that they were, are or will be red. — Janus

That they were, are and will be all red could be a contingent matter, that is it just so happens that all of those kinds of objects have been, are and will be red. — Janus

One predicate is distinct from another if they don't have identical extensions, even if they overlap (as various cases of possibility and necessity do). One predicate is the opposite of another, usually, if one is the complement of the other, includes everything it doesn't and nothing it does. I'm not sure we have an everyday word for only being disjoint, that is, being a subset of the complement. — Srap Tasmaner

That's quite reasonable, but relying on "opposite" to mean different things will just lead to trouble. — Srap Tasmaner

Not Necessarily Red is equivalent to Possibly Not Red. — Srap Tasmaner

What you're missing is that we only have Not Necessarily Red — so we know at least one marble is non-red — but we don't have Not Necessarily Not Red (i.e., Possibly Red), so it is entirely consistent for the set of marbles to be all non-red. — Srap Tasmaner

It is unclear to me why Not Necessary (◇~) is not also equivalent to Possible (◇). — Luke

Not Necessarily is Possibly Not, so that's our existential quantifier. It says you can pick a non-red marble from the set because there is at least one non-red marble to be picked. If you can't pick a non-red marble, that's because all the marbles are red; that's the situation we say we are not in.

And it should be clear that there being at least one non-red marble in the set is consistent with there being only non-red marbles in the set. That is, Possibly Not Red is consistent with Necessarily Not Red. — Srap Tasmaner

and you want to know why it's not equivalent to Possibly P

~▢~P — Srap Tasmaner

I've got my usual urn of marbles, and I tell you that the marbles in the urn are not necessarily red. You can conclude, given that the urn is not empty, that there is at least one marble in the urn that is not red. Good so far? — Srap Tasmaner

It is unclear to me why Not Necessary (◇~) is not also equivalent to Possible (◇).
— Luke

The problem is necessity.

Saying something is true might seem to entail that it could be false, but it doesn't, because what you're saying might be necessarily true. 3 + 4 is 7 doesn't entail that 3 + 4 might not be 7.

So it is with possibility: to say that P is possible might seem to entail that ~P is also possible, but we can't do that because it may be that P is necessary, and that's why it's possible. Same as above: it is possible that 3 + 4 is 7, because it is, and it is necessarily.

Does that make sense? — Srap Tasmaner

So, no, Possible (◇) is the opposite of Not Possible (~◇), and nothing else.

The opposite of Necessary (~◇~) is Not Necessary (◇~). — Srap Tasmaner

This is not a happy use of "opposes"; see below. — Srap Tasmaner

Metaphysically speaking, I take these terms to mean:

1. Impossible = cannot occur
2. Possible = can occur
3. Necessary = must occur

This does not make "necessary" and "possible" the same. It opposes the concepts of 1 and 2 to each other, and the concepts of 2 and 3 to each other. This does not require "possible" to be in a distinct category.
— Luke

Yes, that's exactly the problem. If (1) is defined as opposed to (2), and (3) is defined as opposed to (2), then (1) and (3) must have the very same meaning, by definition. — Metaphysician Undercover

Therefore we need a fix for this problem. — Metaphysician Undercover

All you have here is the meaningless, circular definition, which I objected to earlier. "Necessary" is defined as "not possible", and "possible" is defined as "not necessary". But this is not truthful for the reasons I've given. "Necessary" is properly opposed to "impossible", as I've explained. And "impossible" cannot be opposed to "possible" because this would make "necessary" and "possible" the same. So we need to put "possible" in a place distinct from the category which contains those opposites, necessary and impossible. — Metaphysician Undercover

Whoa! Do I get some sort of prize for bringing this about? — Srap Tasmaner

I agree with all of this, at least in spirit, but you have to be careful about the position from which such a claim is made. We have to be able to say that what is cannot not be without falling into a modal fallacy of treating all truths as necessary. — Srap Tasmaner

MU's point is, I think, a little different: from our position in time, we can only "really" think of the past as fixed, so claims about what was or was not possible in the past, at a time before some event occurred or didn't, are inherently somewhat suspicious. — Srap Tasmaner

You are simply misrepresenting what I said (as is your usual habit) to continue with a strawman argument. I didn't say that it was necessary that you had to have toast instead of cereal. To the contrary, I said that was a choice you made from real possibilities. What I say, is that now, after you've had toast, it is impossible to change that fact, so it is necessary. So I'll repeat, though I doubt it will affect your strawman, before the act, it is possible, after the act, it is necessary. — Metaphysician Undercover

But what about the events that have happened in the past? Is it inherent to the past that an event which occurs at a past time cannot change? Or is that something *else* we know about the past only a posteriori? — Srap Tasmaner

I mean, it's not possible. You're substituting another impossibility for the one I was entertaining: your question (if you were inclined to ask) would be, why don't cups unfall? — Srap Tasmaner

Of course, that's not "possible," given thermodynamics and whatnot, but is it logically impossible? — Srap Tasmaner

All in hopes, if it wasn't clear, of understanding how temporality relates to alethic modality. Is one logically prior to the other? Which one? — Srap Tasmaner

The aftermath of my coffee falling lasts from B to C, at which it is undone; before B, and after C, the coffee has not fallen. — Srap Tasmaner

In what, then, does the immutability of the past consist? Is it brute fact? Could it conceivably not be? — Srap Tasmaner

If the former, then what is actual is/was not necessary.
— Luke

See, you explicitly conflate "is" and "was". There is a reason why we have different tenses for verbs, if you insist on ignoring this, then this discussion is pointless. — Metaphysician Undercover

I've responded to your supposed argument. It is simply based in a failure to recognize the difference in temporal perspectives. Looking ahead in time at future acts, is not the same as looking backward in time at past acts. Therefore, within the minds of human beings, future acts have a different status from past acts. — Metaphysician Undercover

I propose that we look at future acts as "possible", and past acts as "necessary". You are resisting this. Can you explain why? Your argument so far seems to be that if we name past acts as "necessary", then future acts must also be called "necessary". But as I've explained, that is to ignore the difference between how we look at the past and how we look at the future. — Metaphysician Undercover

Are they real possibilities which each have a genuine chance of being the actual outcome, or are they merely a function of our knowledge/ignorance and there is only ever one real possibility?
— Luke

As I said, they are a feature of one's knowledge. However, this does not mean that they are not real or genuine. Knowledge is real and genuine. The realness, or genuineness of the possibilities which one considers is dependent on the scope of one's knowledge of the situation. Sometimes a person will fail in an effort to do something, and sometimes a person might not grasp a possibility which is obvious to someone else. That the possibilities are in one's mind, and are features of how one understands one's current situation, does not mean that they are not real. Nor does it mean that the person has no real choice. — Metaphysician Undercover

Yes, those possibilities are how we think "about" the future, just like we can say something "about" the future. — Metaphysician Undercover

The particular possibilities at t0 are possibilities regarding the future situation at t1; they are not possibilities regarding the present situation at t0. There are no other possibilities (for t0) at t0 other than the actual situation.
— Luke

No, the possibilities are the ones which are present, at the current time. Yes, they are derived from our view toward the future, but they are stated as the possibilities which are present. They are an aspect of one's knowledge. So, "that there will be a sea battle tomorrow", is a possibiltiy present right now in my mind, if I believe this. — Metaphysician Undercover

I'm saying that after the act is carried out it is no longer a possibility in my mind, it is necessary, as what has been carried out, what is actual. — Metaphysician Undercover

What was meant in the quoted passage, was that "possible worlds" referred to logical possibilities for what is the case. If we do not know precisely what is the case in a specific situation, we allow for many different possibilities. — Metaphysician Undercover

The particular possibilities at 10, are no longer possibilities at 11. That's the nature of passing time, things change as time passes — Metaphysician Undercover

No, none of them are possibilities after the act, not even the one you chose, that's the point. You can't have your cake and eat it too. Once you eat the cake, eating it is no longer a possibility. — Metaphysician Undercover

Suppose "possible world" means that if we identify all the possible worlds, one of the possible worlds must be the actual world. That is, we assume such a thing as the actual world, and we assume we've identified all the possible worlds, so necessarily one of the possible worlds is the actual world. Then we proceed to identify one of the possibilities as the actual world, the real world. As soon as we do this, we negate the defined status of "possible" from all the other worlds. They can no longer be the actual world, because we've identified the actual world and it's something else. Since we've named one as "actual", the others can no longer be classed as "possible", without changing the original definition of "possible". — Metaphysician Undercover

I think this is the common misconception of free will, which leads to all sorts of problems. After you have marked the box, engaged in the free will act, we cannot, from that temporal perspective, say that you might have marked a different box. From that temporal perspective, after the fact, it is impossible that you might have done otherwise. You did what you did, and at this time it is impossible that it might be otherwise. And this misconception (straw man), that if you had free will, you might have done otherwise, when you really can't because what's done is done. gives fodder to the determinist argument, . However, this does not change the fact that prior to the act you have many choices, and there are many possibilities for boxes which you might mark. So free will is very real from this perspective, despite the fact that you cannot have dome other than what you did. — Metaphysician Undercover

However, if I recall correctly, you made the absurd claim earlier that "possible" is not the opposite of "impossible".
— Luke

That's right, imposible ought not be considered as opposite to possible, because it leads to the ambiguity of "necessary" which I described and you don't seem to understand. — Metaphysician Undercover

Then you have likewise rendered "possible" as extremely ambiguous and misleading.
— Luke

Yes, "possible" is extremely ambiguous and misleading. But it has been this way for a long time, so it is not I who has rendered it thus. — Metaphysician Undercover

The problem is that when we turn to the temporal nature of reality, what is, is what is necessary. — Metaphysician Undercover

And what is, is in the same category as what is not, as its opposite. Now we would have two very distinct opposites of "necessary", what is possible, and what is not. — Metaphysician Undercover

Yes, this is exactly the problem with defining "possible" like you propose, which I explain above. It renders "necessary" as extremely ambiguous and misleading. — Metaphysician Undercover

...there is no opposite to may or may not be. — Metaphysician Undercover

I understand that, but my point is that if one can know that p but not be certain then it should be acceptable to say "I know that p but I am not certain" — Michael

Does the weather forecaster actually know something — Metaphysician Undercover

Here, you are asserting "In the first scenario it is raining, in the second scenario it is not". Do you know whether or not it is raining in each scenario, in an absolute way? If so, I can give you an answer. If not, I cannot. This is because I cannot say whether Alice has knowledge or not unless I know infallibly whether or not it is raining. — Metaphysician Undercover

According to presentism, if we were to make an accurate list of all the things that exist...there would be not a single merely past or merely future object on the list. Thus, you and the Taj Mahal would be on the list, but neither Socrates nor any future Martian outposts would be included. (Assuming, that is, both (i) that each person is identical to his or her body, and (ii) that Socrates’s body ceased to be present—thereby going out of existence, according to presentism—shortly after he died. Those who reject the first of these assumptions should simply replace the examples in this article involving allegedly non-present people with appropriate examples involving the non-present bodies of those people.) And it is not just Socrates and future Martian outposts, either—the same goes for any other putative object that lacks the property of being present. No such objects exist, according to presentism.

There are different ways to oppose presentism—that is, to defend the view that at least some non-present objects exist. One version of non-presentism is eternalism, which says that objects from both the past and the future exist. According to eternalism, non-present objects like Socrates and future Martian outposts exist now, even though they are not currently present. We may not be able to see them at the moment, on this view, and they may not be in the same space-time vicinity that we find ourselves in right now, but they should nevertheless be on the list of all existing things.

It might be objected that there is something odd about attributing to a non-presentist the claim that Socrates exists now, since there is a sense in which that claim is clearly false. In order to forestall this objection, let us distinguish between two senses of “x exists now”. In one sense, which we can call the temporal location sense, this expression is synonymous with “x is present”. The non-presentist will admit that, in the temporal location sense of “x exists now”, it is true that no non-present objects exist now. But in the other sense of “x exists now”, which we can call the ontological sense, to say that “x exists now” is just to say that x is now in the domain of our most unrestricted quantifiers. Using the ontological sense of “exists”, we can talk about something existing in a perfectly general sense, without presupposing anything about its temporal location. When we attribute to non-presentists the claim that non-present objects like Socrates exist right now, we commit non-presentists only to the claim that these non-present objects exist now in the ontological sense (the one involving the most unrestricted quantifiers). — SEP article on Time

Surely we know our collective fiction (which is the model, which is the world) in exactly the same way, and with the same level of surety, that we know Aragorn was king of Gondor. So, whence surprise?
— Luke

From hidden states. — Isaac

Who said anything about the world surprising us? — Isaac

Since it is possible that our model could be false in at least some respects, and that we could be surprised, it follows that there is more to truth than a mere "collective fiction".
— Luke

This is only true if the terms are interchangeable (that truth is about the model being surprising), otherwise your conclusion doesn't follow, hence you begged the question by assuming that relation in your argument for it. — Isaac

I take the position of redundancy to be that there are no matters outside of language, and that the model is equivalent to the world, whether that is your personal view or not.
— Luke

I really don't know where you're getting that idea from. — Isaac

You didn't say why there should be no surprises using my analogy with "Aragorn was king of Gondor". — Isaac

Because the hidden states the world is a collective model of may be modelled imperfectly. — Isaac

By that logic, you are also begging the question by assuming 'truth' does not refer to such hidden states.
— Luke

I'm not assuming though. That conclusion doesn't itself form part of my argument for it. — Isaac

Come on, at least the bare minimum of effort to fairly represent your interlocutors. It's literally written in the very quote you cited... — Isaac

Therefore, there are no boiling kettles outside of language, either?
— Luke

No. — Isaac

The boiling kettle can't be 'true' since there are no matters, outside of language, which could make it so. — Isaac

You clearly misunderstood what I said. Or, as is often the case with you Luke, you intentionally misrepresented what I wrote. Whatever, I will repeat myself as usual. The same ideas which are knowledge at one time are not knowledge at another time. — Metaphysician Undercover

Why should there be no surprises if the world is the model? — Isaac

Since it is possible that our model could be false in at least some respects, and that we could be surprised, it follows that there is more to truth than a mere "collective fiction".
— Luke

Only if you already beg the very question we're debating by assuming 'truth' refers to the hidden states that the model is of. — Isaac

No one is saying anything about there being 'nothing' outside of language, I don't know where you're getting this from. — Isaac

The boiling kettle can't be 'true' since there are no matters, outside of language, which could make it so.
— Isaac

Therefore, there are no boiling kettles outside of language, either? There are only statements about kettles but no actual kettles?

If something 'outside' of language constitutes the 'kettle' regarding which we're assessing the truth of some property, then what is it?
— Isaac

The kettle itself; not merely talk about a kettle. — Luke

Therefore, there are no boiling kettles outside of language, either?
— Luke

No. Language is what delineates 'kettle' as an object. Without it, there's just 'the stuff that kettles are drawn from'. — Isaac

That was one of my two options: At one time the person claimed to know p, but it turns out later that they did not know p.
— Luke

That's not what I said. — Metaphysician Undercover

What is correct, is that what is at one time called "knowledge", is at another time not allowed to be called knowledge. So the same ideas at one point in time qualify to be called "knowledge", yet at a later time are said not to be knowledge. — Metaphysician Undercover

What I am saying is that p was a part of the person's knowledge at one time, and not-p was a part of the person's knowledge at another time, because knowledge changes. The person clearly knew p, as p may have played a significant role in the person's body of knowledge. So we clearly cannot change this to say that the person did not know p, because this would involve the contradictory conclusion that the knowledge possessed at the time was not really knowledge. — Metaphysician Undercover

That p is true is a judgement. And of course, if one judges that p is true, then this person obviously does not know not-p. So, who is making the judgement that p is true in your example? — Metaphysician Undercover

Obviously it's not the person who knows not-p. — Metaphysician Undercover

Just like the fact that we all 'know' Aragorn was king of Gondor.
— Isaac

I used your example of '"Aragorn was king of Gondor" is true' to demonstrate this. That proposition is part of the "collective fiction" model and it's not possible that it could be false.
— Luke

I don't understand how it's not possible to be false. — Isaac

"Aragorn is the king of Mordor" is false. — Isaac

Why? You're connecting 'truth' to surprise but that's the very connection in question - the degree to which the truth of "the kettle is boiling" is connected to the hidden states that might surprise me. I'm not denying that hidden states can cause surprise I'm denying the link (or the strength of it) between them and the semantic content of a speech act such as "the kettle is boiling". — Isaac

I might have a model of my environment that I interact with and could be surprised by (if I get my predictions wrong, or fail to control it). — Isaac

Correspondence theory seems to want have it that our words somehow try to match that environment. I'm arguing that that's not what our words do. — Isaac

Truth is a property of statements, so the extent to which our words don't match an external world, is the extent to which the truth is unrelated to the external world. — Isaac

I don't follow your argument here. I'm saying that the function of the collective fiction is to reduce surprise about each other's behaviour — Isaac

Firstly one can still be surprised by that very behaviour if, for example, the fiction fails in its task. Second, one can still be surprised by one's environment. The actual response and the act of naming it are two different things. You seem to be conflating the two. — Isaac