SEP describes the thesis that metaphysics is impossible as follows:

Let us call the thesis that all metaphysical statements are meaningless “the strong form” of the thesis that metaphysics is impossible. (At one time, an enemy of metaphysics might have been content to say that all metaphysical statements were false. But this is obviously not a possible thesis if the denial of a metaphysical statement must itself be a metaphysical statement) And let us call the following statement the “weak form” of the thesis that metaphysics is impossible: metaphysical statements are meaningful, but human beings can never discover whether any metaphysical statement is true or false (or probable or improbable or warranted or unwarranted).

The strong thesis seems to refute itself, because any statement about the impossibility of metaphysical truth is itself a metaphysical truth.

What about the weak form of the thesis that metaphysics is impossible? Kant seems to echo this view, but I'm wondering of the current status of this thesis. SEP does not go into detail about this. Much of metaphysics apparently relies on general principles of rationality, such as simplicity, but it's not clear to me how we can apply these here. Of course, we can believe that such rationality is "good", in a general sense, but we really have no justification for it. While rationality may be justified in the sense that it is pragmatic for us in our present situation, I don't see how any principle of rationality can be used metaphysically.

So, what is the status of this thesis within the philosophical community? Have most metaphysicians accepted that they deal with purely (to borrow a term) possible worlds without any relation to the actual world, or do they assert that we can determine metaphysical truths in our present condition?

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    i think you've misunderstood the quote: which seems to claim that the strong thesis is only about impossibility, not falsity. if the latter, then it would be enough to show that it is a metaphysical statement (though i'm not sure how anyone can show that in the abstract) to show it is incoherent. but, instead, it has to be shown that the thesis depends upon metaphysical statements, that no meaningful case can be made for it. quite why the incoherence of the basis is more difficult to show than the thesis, i'm not sure (though as stated i'm not sure why the latter is said to be easy)
    – user38026
    Commented Aug 15, 2019 at 21:49
  • it seems that 'metaphysics' includes refutations of metaphysical theses. but surely one could counter that, no, 'metaphysics' proper always advances a thesis that is not just a refutation. this may be anti-intellectual and gauche, to treat it in the abstract, outside the dialectic etc. of evolving positions. but it is not open to the charge of self referential incoherence to the same extent as LP, as the LP's would have had to find another type of meaning to avoid incoherence. rather than merely using 'denial' assumed by the strong thesis already
    – user38026
    Commented Aug 15, 2019 at 22:01
  • i don't see any problem with a claim like there are no true non negative existential metaphysical statements. not in the abstract, without reasons for supposing it. i'm ranting, and may seem incoherent.
    – user38026
    Commented Aug 15, 2019 at 22:24
  • Big M metaphysics, discerning the nature of reality by reason alone, or by some extraordinary intuition, is now largely confined to religious discourse. Small m metaphysics, pragmatic and fallible, that covers speculative aspects of inquiry is very much alive, and undergoes a revival, see What are some real-life applications of metaphysics? One does not need "real justification" of metaphysical speculations as long as they are put to work to unify knowledge or generate conjectures, judged as fruitful or not, adjusted, etc.
    – Conifold
    Commented Aug 15, 2019 at 23:23
  • @Conifold Isn't there some middle ground here? For example, the mind-body problem. It isn't quite as pragmatic as something like formal ontologies in computer science, but not quite as " purely metaphysical" as religious discussions. Or, again, is this simply a discussion about possible worlds? Also, I'd fully expect this to be a topic of debate mainly in the context of religion, so it's not entirely clear to me why that's significant.
    – Josh
    Commented Aug 16, 2019 at 0:02

1 Answer 1


According to Borchert's entry on metaphysics , metaphysics is the act of attempting to account for the "fundamental nature of being", and is "concerned with the contours of the categories of entity postulated or presupposed" real or imagined to encompass "a complete, coherent ontology, embracing all that is necessary to capture the correct account of the world".

First, there is no monolithic philosophical community. Many communities of philosophers exist, and they may hold widely divergent views of the world and the state of 'philosophy' whatever that may be. I know of no statistic which would be required to actually answer your question (coming from a doctrine of empiricism), but I would argue that most metaphysicians believe their work has some relevance to objective (intersubjective, physical, actual,...) reality. Here's a journal of metaphysics Metaphysics Metaphysics Collaborative which contains an article on William of Ockham's views on the Aristotelian ontological status of artifacts “Nothing in Nature Is Naturally a Statue”: William of Ockham on Artifacts. It has long been the hallmark of metaphysics to engage in debate over what is the proper relation between ontology and epistemology, for instance, and ontology and epistemology have a direct bearing on "reality".

The nature of metaphysical discourse has evolved necessarily since the time of Aristotle, and a number of philosophical problems and approaches have arisen. Borchert's cites a spectrum of responses of differing ontological commitment: from realism to antirealism, for instance. Metaphysics is a continuing dialog that discusses ideas such as the universal and the particular.

It is certainly a hallmark of metaphysics that it is rationalist far more than it is empirical in content, but remember that of the most natural of the three logical methods of inference (deduction, induction, and abduction), metaphysics relies, like all philosophy on intuition and meaning, both ideas that are only recently coming to light (historically speaking) in terms of cognitive processes. While the edifice of Western philosophy has relied heavily on the scientific method, science itself has discerned that the way in which philosophers think is itself subject to forces and rules. (See the cognitive science discipline of cognitive semantics)

Philosophy has often been disparaged by scientists (Bill Nye and philosophy) as being unpragmatic and excessively rational, in the same way metaphysics has been seen by some philosophers. But the obvious truth is, that when reasoning from first principle, it is necessary to select first principles, and how is that to be done? Modern psychology has shown that rational decisions are rooted in the limbic system anyway. (See the historical evolution from Euclidean to non-Euclidean geometries from the field of the philosophy of mathematics to see an evolution in metaphysical thinking).

Philosophers who have engaged in metaphysical speculation since Kant have included A.J. Ayer, among others. While there are many brilliant rejections of metaphysics, the fact seems to be that metaphysics serves as a useful category and a pragmatic function for the majority of philosophers and continues as vibrant source of debate. There are many justifications for metaphysics, including those supported by cognitive science. Whether or not you buy a rejection is largely a result of your metaphysical presuppositions.

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