It's very neat. But yes, quite mad. — Banno

:lol:

Kripke was an essentialist: he believed individual identity was associated with its essence - a subset of an individual's properties.

So his theory of possible worlds is contingent upon essentialism being true. It falls apart if essentialism is false. My position has been that it is false. Can you defend essentialism?

As I understand it, for Lewis, it is not necessary to select one of the possible worlds as real, as all possible worlds are as real as each other. All possible worlds are real concrete worlds, actual ontological worlds. — RussellA

Yes that's exactly the problem. What we know as the independent, physical world, source of empirical observations, can no longer be accepted as such. It gets barred off as a sort of unreal illusion, and what we're left with is an extreme idealism where the ideas (possible worlds) are the reality. Something like this is necessary to fulfill the second truth condition listed by the SEP:

(ii) its designated “actual world” is in fact the actual world, — SEP

To fulfill the criteria for "truth", the actual world, within the possible worlds model, as one of the possible worlds, must "in fact" be the actual world. This is the issue @Banno and I debated endlessly in the other thread. The position that Banno insisted on, which I insisted is clearly false, is that the actual must be possible. This means that the actual world (and this is the factual "actual world") must be a possible world. Banno tried to dismiss this as an actual world which is distinct from the metaphysically actual world. But this means that the metaphysically actual world is not the true actual world, leaving the source of empirical observations as some sort of illusion.

Of course this creates a unique problem. We really only have empirical observations to base our stipulation of "actual world" on, in the modal model. But this realm of empirical observations is illusory, as it cannot be "the actual world". The actual world has to be one of the possible worlds. Then the use of empirical observations to produce "the actual world" in the model, is not justifiable. Then we have a whole number of concrete possible worlds, one of which is designated "the actual world" and is in fact the actual world by that stipulation, but the designation is unjustifiable.

So "infinite possibility" is the point: possible world analysis of an object has no bounds. — Relativist

Infinite possibility is the problem. Look at the first truth condition listed by the SEP:

(i) its set W of “possible worlds” is in fact the set of all possible worlds, — SEP

Since possibilities can be boundless, any set of possible worlds which we produce can never be "in fact the set of all possible worlds". And this is where the Platonist presumption becomes very clear. The possible worlds we present, are really ideas which we produce. But it is implied that there is an independent set of all possible worlds.

So this is precisely the problem with Platonism. We assume the existence of independent ideas, independent truths. But then for us to properly have truth, the ideas which we have, must be the very same as the independent ideas. This is impossible for us, and the impossibility manifests as this issue with infinity.

The opposite extreme: 100% of an objects properties (all of which are qualitative) at time t1 are necessary and sufficient for being that object at t1. This is my view. — Relativist

That is my view too, and I think it is the common understanding of "numerical identity", which is what the law of identity deals with. The issue I find is that ultimately, even this fails. We come to realize that it is impossible for us human beings, with our limited capacities, to completely understand all of an object's properties at t1. As devoted philosophers though, we want to know why we cannot understand all of a thing's properties at a specific time. Then we come to realize that the reason is that there is no such thing as t1, because time is always passing at any specified time. Therefore at any specified time, t1, there is actually duration, change is actively occurring. So "100% of an objects properties" doesn't quite fulfill "necessary and sufficient for being that object", because some parts are actively changing and those aspects of the thing cannot be described as properties.

As Aristotle pointed out, the parts which are changing defy the fundamental laws of logic, Because the object must either violate the law of noncontradiction (has and has not the property which is becoming), or violate the law of excluded middle (neither has nor has not that property). Aristotle demonstrated that what becoming, or change is, is fundamentally incompatible with "properties" of being. So properties are understood as form, and he proposed "matter" as potential, to represent that part of a thing which is changing, as the possibility for properties. From this perspective, at t1 (which must actually be a duration), an object consists of properties (form), but knowing all the properties will not produce a complete knowledge of the object, because the representation of t1 as a stopped point in time, cannot be true. Time is always passing, so a point in time, as t1, is a false representation which would properly be represented as a duration of time. In that duration of time change is occurring, and so we need to include "matter" as the potential, or the possibility for properties.

Kripke and I would say that "What if Nixon didn't win the 1972 election?" is a question about Nixon. — Banno

I explained the fault with this way of thinking explicitly, when we discussed "the circumstances" under which I was the fellow who won the lottery. Your statement is not about Nixon. Nixon won. Therefore to talk about a person who did not win is not to talk about Nixon. That's plain and simple.

To entertain the idea of NIxon not winning, is to think of different circumstances, just like if I was to think of myself as having won the lottery would be to think of different circumstances. Therefore "what if Nixon didn't win the 1973 election?" is clearly not a question about Nixon. It is a question about the circumstances. The question asks how would the circumstances be different if it had been the case that Nixon had not won. This is clear because you place "Nixon" within that context of the 1972 election, and you make a question about changing the context.

The opposite extreme: 100% of an objects properties (all of which are qualitative) at time t1 are necessary and sufficient for being that object at t1. This is my view.
— Relativist

That is my view too — Metaphysician Undercover

The implication is that there is only one possible world: the actual one. Do you agree?

When we conceive of (allegedly) possible worlds, we are constucting a fiction. IMO, the semantic framework can be useful for analyzing possibilities, but the exercise should not be taken too seriously.

It's not the case that logic necessarily implies metaphysics, but using metaphysical terms like "thing" and "identity" do imply metaphysics. And if you believe that epistemology can be separated from its metaphysical grounding you are mistaken. — Metaphysician Undercover

:up:

We both agree that there is a very clear and significant difference between "the actual world" in a modal model, and "the actual world" as a real, independent metaphysical object. However, you persistently refuse to apply this principle in you interpretation of modal logic. And, when I insist on applying this principle in our interpretation of modal logic, you reject me as erroneous, and refuse to include me in your "game". — Metaphysician Undercover

Yes, and this critique can be drawn out in various ways. The question of whether a first-order quantifier quantifies over imaginary entities has no real answer, and this is why modern philosophers can debate the topic ad nauseum. The underlying issue is the fact that modern philosophy is filled with metaphysical muddle. The attempt to devise a logic which leaves metaphysical questions untouched is incoherent. In the case of first-order logic this manifests with the metaphysical confusion surrounding ‘thing’ or ‘one’, which Aristotelians know to be transcendental terms but moderns confuse for category terms. The modern logician says, “For all x…,” but when asked what he actually means by ‘x’ he has no idea. He doesn’t know whether imaginary entities count, or whether theoretical entities count, or whether propositions themselves count, etc. In essence he does not know to which of the categories of being his quantifier is supposed to apply, and his presuppositions ensure that he will be unable to answer such a central question.

Kripke was an essentialist: he believed individual identity was associated with its essence - a subset of an individual's properties... So his theory of possible worlds is contingent upon essentialism being true. — Relativist

Yes, although in a way very different to others hereabouts. An individual's essence, for Kripke, consists in those properties that the individual has in every possible world in which it exists. Kripke does not start with a prior metaphysical theory of essences and then build modality on top of it. He starts with modal semantics (possible worlds, necessity, rigidity) and then derives essentialist claims as consequences of that framework. So the claim that “Kripke’s theory of possible worlds is contingent on essentialism being true” gets the explanatory order wrong. Essence is explained in terms of necessity, not necessity in terms of essence.

This means that the actual world (and this is the factual "actual world") must be a possible world. — Metaphysician Undercover

The alternative, as has been pointed out, is that for Meta the actual world is impossible.

The rest, again, mischaracterises and misunderstands modal logic.

the claim that “Kripke’s theory of possible worlds is contingent on essentialism being true” gets the explanatory order wrong. Essence is explained in terms of necessity, not necessity in terms of essence. — Banno

The "explanatory order" doesn't falsify the logic: there's s logical dependency on essentialism. But go ahead and explain essence.

Logic learned to free itself from ontology. Not entirely; the domain, and the notion of "something", remain. That's no bad thing. Those who cannot see the advances since the logic of Aristotle suffer a sort of intellectual myopia.

...there's s logical dependency on essentialism — Relativist

Again, that is the cart before the horse. For Kripke Essence is a consequence, not a beginning.