On the other hand, I'd not agree that this is the fundamental or primary category of existence. — Pantagruel
As well you shouldn’t, your “this” being understood as the general conception “property”. The fundamental ground of properties is their capacity for measurement, or, the establishment of the inference of some relative quantity. Existence does not carry the burden of being measurable. If, instead, existence is merely a necessary condition, it need not be subject to measurement, nor the ambiguities of logic-linguistic arguments, and above all, properties need not be a fundamental category of existence.
And here’s why: anything ever talked about, or thought about, is from the perspective of human rationality. So everything absolutely must relate to us and us alone. Properties are that which we assign to objects in order, on the one hand, to arbitrate them one from another, or, which is the same thing, how they relate to each other. On the other hand, we assign conceptions to understand how they can be told apart, or, which is the same thing, how they relate to us. We use properties a posteriori for the former, but we use the categories a priori for the latter. Properties can have no bearing on the respective objects to which each set belongs, and the assignment of properties presupposes the objects to which they belong. There is no need to quantize that which doesn’t exist.
Fine. But what tells us it is not a waste of reason to assign properties? We don’t just willy-nilly think....this will be red, that will be 4” long, the other will be 16 lbs. Still fine. But to say we assign properties to that which is met with perception only tells us there is something there, but not whether it is proper that it should be there. Mirages are given properties, because they appear to perception, but experience informs us they do not exist.
OK, so what can we use to tell us that which appears really is something that actually and indubitably deserves the properties reason works so hard assigning to it. In other words, why do we say it is a waste of time talking about something of which we know nothing. And why for some of us, it is a waste of time to talk about that which is either highly unlikely or only possible? Because reason doesn’t want to waste its time, that’s why. (Illustrative figure of speech here; reason doesn’t have wants)
For warrants that reason does not waste its time, there are twelve, but only three have bearing on this dialogue: we may be assured the properties we assign are justified 1.) if that which appears exists, in which case the properties will be dependent, because of cause and effect; 2.) if that which appears necessarily exists, in which case the properties we assign will be certain, because of non-contradiction; and 3.) if that which appears possibly exists, re: mirage/hallucination, physical indiscernibles, in which case the properties will be merely contingent and subject to falsification.
In all those cases, the commonality is the existence of something outside us. Hence, it is logically justified to conclude that existence is the necessary condition for reason to assign properties to things outside us. It follows that things merely thought, residing inside us, not given from sensibility, do not warrant properties, and if they don’t warrant properties, they don’t warrant existence. This is not to say things merely thought are not real in some way, but real with respect to the thought alone, whereas the real with respect to thought AND sensibility, is a different sense of real, which is given the name “existence”.
So to answer your question directly.....no, I most emphatically not saying existence is a property.
BOOM!!!!