Metaphysics has been criticised as unscientific, speculative, and redundant. But any critic of metaphysics inevitably ends up making metaphysical claims of their own. Metaphysics is in fact inescapable – all of our thinking is underpinned by it, and those who ignore it simply espouse an unexamined and possibly faulty metaphysics, argues Robert Stern.
This is the seventh instalment in our series The Return of Metaphysics, in partnership with the Essentia Foundation.
Read the series' previous articles The Return of Metaphysics: Hegel vs Kant, The Return of Idealism: Hegel vs Russell, Derrida and the trouble with metaphysics, The Return of Metaphysics: Russell and Realism, After Metaphysics: Rorty and American Pragmatism, and Wittgenstein was a Metaphysician.
In slipping from the glory days of being treated as first philosophy, to the role of mere handmaid of science, to more recently being dismissed as meaningless verbiage, the once proud discipline of metaphysics might seem to be in terminal decline. While its aim is to tell us about the fundamental nature of reality, it is now commonly accused of relying on conceptions of the world and on methods of inquiry that have been surpassed, and that although once some confidence in it may have been warranted, this cannot be the case today. For example, we can no longer share the belief in a universe ordered by a rational and benevolent deity that may formerly have underpinned the kind of rationalist metaphysical theorizing of a Leibniz. It may therefore seem inevitable that metaphysics is a part of philosophy that we must now give up.
Some, of course, choose to defend metaphysics by replying that it does not in fact rely on any such theistic underpinnings, and can be pursued intelligibly within a more contemporary view of the world. Indeed, metaphysics continues to have some distinguished proponents. But, in the spirit of Étienne Gilson’s famous aphorism that ‘philosophy always buries its undertakers’, I want to consider here a more radical option: namely, that there is something self-undermining or incoherent in the very attempt to dispense with metaphysics, with the result that it will always be able to outlive those who try to do away with it. I will consider two such arguments: the first is that to criticise metaphysics is itself inevitably to rely on certain metaphysical claims and indulge in various forms of metaphysical theorizing, thereby making metaphysics impervious; and the second is that metaphysical ideas underpin all our thinking, thereby making metaphysical reflection on those ideas indispensable.
Science can’t overturn metaphysics, because in attempting to do so, science ends up making claims with the kind of scope and theoretical abstraction that means it in effect becomes a form of metaphysics itself
If you’re objecting to metaphysics, you’re doing metaphysics
Critics of metaphysics typically adopt the perspective of some other discipline (usually the empirical sciences) to claim that the worldview on which metaphysics relies has been surpassed, making metaphysics redundant. Then one response is: whatever this discipline may be, it is either claiming to present a picture of the world of sufficient scope that it then itself amounts to a metaphysics, or it is not, in which case it must still leave room for metaphysics, as its own view of the world remains too narrow to rule this out or act as a competitor. Thus, it is argued, only a scientific conception that itself involves some further extra-scientific and hence metaphysical commitments can in fact challenge the claims of metaphysicians. For example, if someone asserts that science disproves the existence of God, they are in fact going beyond science and venturing into metaphysics. Equally, if science is said to be silent on the issue, that means there remains a space for metaphysical theorizing. The idea, then, is that science can’t overturn metaphysics, because in attempting to do so, science ends up making claims with the kind of scope and theoretical abstraction that means it in effect becomes a form of metaphysics itself.
This defensive strategy certainly has its charms, and it may well be the case that some critics of metaphysics have gone beyond their brief and engaged in various forms of metaphysical theorizing themselves. However, this strategy rests on the assumption that the challenge to metaphysics must come in the form of direct critique, which is then said to involve metaphysical commitments – but the challenge could also take a different form which does not involve any such commitments, namely what might be called benign neglect. That is, the critic of metaphysics could simply eschew various forms of grand metaphysical theorizing, and stick to their own disciplinary boundaries – for example, by asking whether certain laws hold with empirical necessity in this world and others like it, and not asking whether they hold with metaphysical necessity in all possible worlds; or asking about the processes underpinning human life in this world, and not speculating about how life might be possible in the next one. Of course, in some sense, this still leaves metaphysics unrefuted – but as a strategy, it could come to the same as a refutation, in just leaving metaphysics to wither on the vine.
The metaphysician’s response could then be that humans cannot help but be interested in these questions – overlooking them is not really an option and so metaphysical speculation will never go away. But here, the critic’s reply might be that the problem with these sorts of metaphysical inquiries, even if we find them irresistible, is that they do not seem to yield any results. Metaphysical speculation is just that, mere speculation, argues the critic – and we should therefore turn to more productive intellectual pursuits and forms of inquiry that can produce results. If some of us cannot help but keep speculating about metaphysical questions, the critic continues, that’s no evidence in favour of metaphysics, it’s rather evidence against the intellectual wisdom of those doing the speculating.
Thus, it seems, the argument from imperviousness can be side-stepped by the critic of metaphysics on the grounds that metaphysics is an optional indulgence that we may have to learn to do without, given its lack of progress. But can we really do without it? This is where the second argument I want to consider might come in, namely the argument from indispensability. I think this is an argument that can be found in the work of the 19th century American pragmatist C. S. Peirce, and before him in the philosophy of the German idealist G. W. F. Hegel.
For both Hegel and Peirce held that all our thinking, even of the most ordinary and banal kind, is shot through with various metaphysical assumptions
You’re doing metaphysics, even if you don’t notice
Both Peirce and Hegel were fully aware of the critical case against metaphysics. For Peirce that case was best made by fellow pragmatists such as William James, and for Hegel by Immanuel Kant. But while both philosophers accepted the power of these critiques, meaning that metaphysics could not proceed as before, they nonetheless retained the conviction that metaphysics cannot be given up, and those who think it can are fooling themselves and committing a potentially dangerous mistake. For both Hegel and Peirce held that all our thinking, even of the most ordinary and banal kind, is shot through with various metaphysical assumptions, since all our thinking is grounded in various metaphysical concepts that shape how we think about the world: being, cause, substance, whole, essence and so on, are all such metaphysical categories. We take these fundamental categories for granted; but then the consequence of this unreflective stance can be deep puzzlement and errors, not only in philosophy but also in ordinary life. For, our fundamental categories can turn out to be inadequate in various ways – it is then the vital task of the metaphysician to reflect on them more deeply, and perhaps change the way in which we conceive of these ideas.
On this account, then, there are two ways in which metaphysics is indispensable: firstly, we are intrinsically metaphysical creatures, in that we all have a fundamental scheme of thinking about the world, our ontology to use the philosophical jargon, our conception of Being, of what is, and this is not something we can dispense with if we interact in a thinking way with the world at all. Secondly, we must engage in metaphysical inquiry, as we must continue to reflect on that conception, as if we do not, we will be unable to avoid the ways in which we are being led astray. Thus, given that we are metaphysical creatures, we cannot in good conscience give up doing metaphysics. Peirce puts this view quite clearly:
Find a scientific man who proposes to get along without any metaphysics—not by any means every man who holds the ordinary reasonings of metaphysicians to scorn—and you have found one whose doctrines are thoroughly vitiated by the crude and uncriticized metaphysics with which they are packed. We must philosophize, said the great naturalist Aristotle—if only to avoid philosophizing. Every man of us has a metaphysics, and has to have one; and it will influence his life greatly. Far better, then, that that metaphysics should be criticized and not be allowed to run loose. A man may say ‘I will content myself with common sense.’ I, for one, am with him there, in the main. I shall show why I do not think that there can be any direct profit in going behind common sense—meaning by common sense those ideas and beliefs that man’s situation absolutely forces upon him. We shall later see more definitely what is meant. I agree, for example, that it is better to recognize that some things are red and some others blue, in the teeth of what optical philosophers say, that it is merely that some things are resonant to shorter ether waves and some to longer ones. But the difficulty is to determine what really is and what is not the authoritative decision of common sense and what is merely obiter dictum. In short, there is no escape from the need of a critical examination of ‘first principles’. 
Peirce’s central claim is that there is no position – either in ‘common sense’ or in empirical science – that is free of metaphysical assumptions and commitments of various kinds, and while that can be perfectly harmless, it can also cause us problems unless we stand ready to critically examine those assumptions and commitments, and thus engage in metaphysics. Thus, Peirce warns: ‘Those who neglect philosophy have metaphysical theories as much as others—only they [have] rude, false, and wordy theories’ .
Moreover, though Peirce does not refer to him explicitly in this context, a similar view is to be found in Hegel. As Hegel puts it:
[E]veryone possesses and uses the wholly abstract category of being. The sun is in the sky; these grapes are ripe, and so on ad infinitum. Or, in a higher sphere of education, we proceed to the relation of cause and effect, force and its manifestation, etc. All our knowledge and ideas are entwined with metaphysics like this and governed by it; it is the net which holds together all the concrete material which occupies us in our action and endeavour. But this net and its knots are sunk in our ordinary consciousness beneath numerous layers of stuff. This stuff comprises our known interests and the objects that are before our minds, while the universal threads of the net remain out of sight and are not explicitly made the subject of our reflection. 
On this account, every thought or claim we make about the world, from the most trivial (‘the sun is in the sky’) to the most significant (‘there is no such thing as society’, ‘evolution makes teleological thinking redundant’, ‘brain structure controls behaviour’) is shot through with metaphysical assumptions concerning the nature of individuals, causes, grounding, relations and so on. And if we don’t reflect on this, and make efforts to get our metaphysics right, then we risk the kind of scientific, social, and ethical errors that Hegel catalogues at length in his Phenomenology of Spirit, and elsewhere. Like Peirce, Hegel is thus scornfully dismissive of attempts by contemporary empiricists to say that they don’t need to care about metaphysics, as they can avoid any of these assumptions: ‘It is true that Newton expressly warned physics to beware of metaphysics; but to his honour, let it be said that he did not conduct himself in accordance with this warning at all. Only the animals are true blue physicists by this standard, since they do not think; whereas humans, in contrast, are thinking beings, and born metaphysicians.’ 
The aim is not merely to describe our metaphysical concepts, but to see what their shortcomings are, and, as a result, to improve them
A clear advantage of this indispensability argument over the previous imperviousness argument is that on this account, metaphysics cannot be simply ignored in favour of some other approach, since metaphysics is bound up with any discipline. Moreover, it also leaves metaphysics less vulnerable to the worry about not making progress. For, if we understand that metaphysics is always operating in the background of any claim, we can be optimistic that thinking differently about certain key categories has led to views of the world that make better sense of things. For example, as Hegel argues, the category of person made it possible to treat human beings with an equality that was not possible before, or in a more recent case, new conceptions of causality have been required to make sense of quantum theory.
It might be said, nonetheless, that this endeavour is not really metaphysics proper, as it is merely the delineation of our own, human conceptual scheme – not any grand grappling with Being per se. P F. Strawson famously called this more modest endeavour ‘descriptive metaphysics’, as the attempt to ‘describe the actual structure of our thought about the world’, but without thereby claiming to tell us anything fundamental about the world itself.Likewise, Kant characterised his project as replacing ‘the proud name of an Ontology’ with ‘the modest title of a mere Analytic of pure understanding’. This approach, however, neglects the critical element that Peirce and Hegel think is fundamental to our investigation of these concepts, and which therefore makes it revisionary rather than descriptive. For, the aim is not merely to describe our metaphysical concepts, but to see what their shortcomings are, and, as a result, to improve them. If this process can be carried out, what reason have we got other than a dogmatic, unmotivated scepticism for thinking that the scheme we end up with is not true of reality itself?
Rumours about the demise of metaphysics thus turn out to be premature, and it will always outlive those who come to bury it .
 C. S. Peirce Collected Papers (Harvard University Press, 1931–58) 1.129.
 Peirce, Collected Papers 7.579.
 G. W. F. Hegel, Introduction to the Lectures on the History of Philosophy, trans T. M. Knox and A. V. Miller (Oxford University Press, 1985), pp. 27–8.
 Hegel, Encyclopedia Logic, §98 Addition
 P. F. Strawson, Individuals (Methuen, 1959), p. 9.
 Immanuel Kant, Critique of Pure Reason, A247/B303
 I am grateful to Luca Barlassina, Fraser MacBride and Adrian Moore for very helpful comments on previous versions of this article.