We often speak of existence commonsensically – coffee exists, my wife exists, etc. But modern analytic philosophy frequently deals of existence in a different manner and does not treat existence similarly to how it treats other properties of things – that is, as a property of individual objects. Rather, existence is seen as a property of properties (i.e. a second order property). Thus, according to what’s been called the Frege-Russel-Quine view of existence, to say that coffee exists isn’t to say that coffee has the property of existence. Instead, it’s to say that some property (say, being coffee) has an instance.
Quickly, one especially devastating objection to the Frege-Russel-Quine view of existence, as mentioned by Nevitt and McGinn, is that “analysis in terms of property instantiation presupposes existence, since an individual or object must exist in order to instantiate any properties.”
To again quote Nevitt quoting McGinn, “Take the statement ‘planet exist,’ and now consider Vulcan (the mistakenly posited inter-Mercurial planet). Does Vulcan instantiate the property of being a planet? If so, then the analysis of existence in terms fo property instantiation is mistaken, since Vulcan does not in fact exist, so its instantiating the property of being a planet does not show that planets exist. But if Vulcan does not instantiate the property of being a planet, of course that can only be because it does not in fact exist, which shows that existence is presupposed by property instantiation, rather than being explained by it. This suggests that the existential quantifier can be interpreted as meaning, ‘For some x, x exists and x is…” where ‘exists’ is used as a first-order predicate.”
In other words, modern analytic philosopher isn’t talking about existence so much as setting rules for how to talk about talking about existence. It is thus inadequate to analysis reality at its most basic level (existence) and should be supplemented by Thomistic insights.
PS – Gaven Kerr offers his own critiques of analytic philosophy from a Thomistic perspective here (see QnA section).