Apply the label "necessitarianism" to my view if you like
Sorry, I don’t understand what you are saying then. You seem to keep flip-flopping. First you mentioned that everything exists necessarily such that there is no way they could have failed to exist—which simply is necessitarianism—and then you turn around and say that you do believe that there may be ways that some things could fail to exist.
Here’s what I am thinking you are attempting to convey, and correct me if I am wrong: saying that a thing could have failed to exist if its parts did not get so arranged (or did not exist) does not demonstrate that it could have failed to exist because it may be the case that there were no other causal possibilities such that it would not have existed. Is that right?
You apparently believe contingency is the default: if necessity isn't proved (or accounted for), contingency should be assumed. I believe the converse: if contingency can't be proved (or accounted for), then necessity should be the default
No, I am using them in the traditional sense. The modality of possibility is about a thing not contradicting the mode of thought used to conceive it: this is not the same thing as conceivability. There are three modes of possibility (traditionally): metaphysical, physical, and logical.
Metaphysical possibility is such that a thing could exist in a manner that does not violate the nature of things; physical possibility such that a thing could exist in a manner that does not violate Nature (viz., physics); and logical possibility such that a thing could exist in a manner that does not violate laws of logic.
This is not the same as conceivability. E.g., it is physically impossible to jump to the moon but conceivable to jump to the moon; it is metaphysically impossible for H20 not to be water but it is conceivable; it is logically impossible for a != a but it is (to some extent) conceivable.
Moreover, contingency is the dependence of one thing on another for its existence; and necessity is the independence of a thing on any other things for its existence.
I think, for you, contingency is the possibility of non-existence for an existent thing (whether it be in the past, present, or future); and necessity is the impossibility of non-existence for an existent thing (ditto). Is that right?
In my sense of the term, a table is contingent upon its parts; and, if causal determinism or necessitarianism is true, could not have failed to existence.
My point is that the OP depends on my kind of contingency in terms of what the word refers to in its underlying meaning; and you cannot wipe this away by engaging in a semantic dispute about how to define contingency.
That depends on the metaphysical system you're using to account for it
Causality is traditionally and widely accepted as explanations of why a thing is the way it is. What you are probably thinking of is physical or material causality.
My impression is that yours depends on a form of essentialism that considers an object's identify to be associated with an essence, to which "accidental" (contingent) properties may attach
That is a fair assessment of the OP, but I don’t think this is true for the subsequent short-hand arguments I gave. It depends solely on the idea that this being depends on its parts to exist even if it could not have failed to exist; no different than how, e.g., platonic forms depend on each other atemporally.
Even if you don’t think there’s an essence to a, e.g., chair; I think you can agree that that particular chair would not exist if its legs, the wood it is made out of, etc. did not exist and you can also simultaneously agree that the chair, under your view, could not have failed to exist.
Without contingent properties, your argument from composition fails. That's because an object's constituents are an identity to the object itself.
No. The chair still depends on its parts to exist even if it could not have failed to exist. The chair does not exist as a brute existence.