Why metaphysics is impossible

As such, the major premise simply offers the most general definition of substance, and thus expresses the most general rule in accordance with which objects might be able to be thought as substances. Nevertheless, in order to apply the concept of substance in such a way as to determine an object, the category would have to be used empirically.

Unfortunately, such an empirical use is precluded by the fact that the alleged object to which it is being applied is not empirical. This same kind of complaint is lodged against each of the paralogistic syllogisms that characterize Rational Psychology.

The personal identity of the soul is attacked on similar grounds. In each case the metaphysical conclusion is said to be drawn only by an equivocation in the use or meaning of a concept of the understanding. The hypostatization of this idea, therefore, although it may be natural, is deeply problematic. The arguments, in other words, involve fallacies that vitiate their conclusions. More specifically, the demand for the unconditioned, and the idea of the soul to which it gives rise, may be construed regulatively as devices for guiding inquiries, but never constitutively — never, that is, as yielding grounds for any a priori synthetic knowledge of a metaphysical self given immediately to pure reason.

There are also excellent discussions to be found in Allison , , Bennett , Buroker , Guyer , Wuerth , Bird , Ameriks , Melnick , Dyck , Proops The second discipline of rationalist metaphysics rejected by Kant is Rational Cosmology. Not only does Kant address himself to the task of discounting the metaphysical arguments in cosmology, but the resolution to some of these conflicts provides, he claims, an indirect argument for his own transcendental idealism.

Thus, the case here differs from the paralogisms and, as we shall see, from the Ideal. The reason for this difference resides in the nature of the idea of reason in question. Unlike the soul and God, which are clearly supposed to be non-sensible metaphysical entities, the sum total of all appearances refers specifically to spatio-temporal objects or events. For with respect to each problem addressed the finitude vs. More specifically, one can either think the unconditioned as an intelligible ground of appearances, or as the total even if infinite set of all appearances.

Unfortunately, each of these conceptual strategies is unsatisfying. Worse, the antithesis arguments, in refusing to go beyond the spatio-temporal realm, end up being just as dogmatic as their opposites, for the assumption is that whatever holds within space and time also holds generally. To assume this is to take what are for Kant merely subjective features of our intuition forms of sensibility, space and time to be universal ontological conditions holding of everything whatsoever.

If the conditioned is given, then the whole series of conditions, a series which is therefore itself absolutely unconditioned, is also given. Consequently, the entire series of all conditions of objects of the senses is already given. There are a number of problems with this argument, according to Kant. The rational assumption that the total series of all conditions is already given would hold only for things in themselves.

In the realm of appearances, the totality is never given to us, as finite discursive knowers. As finite sensible cognizers, however, we shall never achieve an absolute completion of knowledge. To assume that we can do so is to adopt the theocentric model of knowledge characteristic of the dreaded transcendental realist. This hypostatization of the idea of the world, the fact that it is taken to be a mind-independent object, acts as the underlying assumption motivating both parties to the two mathematical antinomies.

The first antinomy concerns the finitude or infinitude of the spatio-temporal world. The thesis argument seeks to show that the world in space and time is finite, i. The antithesis counters that it is infinite with regard to both space and time. The second antinomy concerns the ultimate constitution of objects in the world, with the thesis arguing for ultimately simple substances, while the antithesis argues that objects are infinitely divisible.

The alleged proponent of the antithesis arguments, on the other hand, refuses any conclusion that goes beyond the sensible conditions of space and time. According to the antithesis arguments, the world is infinite in both space and time these being infinite as well , and bodies are in accordance with the infinite divisibility of space also infinitely divisible.

In each of these antinomial conflicts, reason finds itself at an impasse. Satisfying the demands placed by our rational capacity to think beyond experience, the thesis arguments offer what appears to be a satisfying resting-place for explanation.

How does Kant demonstrate this? Both the thesis and antithesis arguments are apagogic, i. An indirect proof establishes its conclusion by showing the impossibility of its opposite.

Thus, for example, we may want to know, as in the first antinomy, whether the world is finite or infinite. We can seek to show that it is finite by demonstrating the impossibility of its infinitude.

Alternatively, we may demonstrate the infinitude of the world by showing that it is impossible that it is finite. This is exactly what the thesis and antithesis arguments purport to do, respectively. The same strategy is deployed in the second antinomy, where the proponent of the thesis position argues for the necessity of some ultimately simple substance by showing the impossibility of infinite divisibility of substance, etc.

Obviously, the success of the proofs depends on the legitimacy of the exclusive disjunction agreed to by both parties. The world is, for Kant, neither finite nor infinite. The opposition between these two alternatives is merely dialectical. In the cosmological debates, each party to the dispute falls prey to the ambiguity in the idea of the world. Kant thus structures his analysis of the mathematical antinomies by appealing to the general dialectical syllogism presented at the end of section 4.

Problems stem from the application of the principle expressed in the first premise to the objects of the senses appearances. Here again, Kant diagnoses the error or fallacy contained in this syllogism as that of ambiguous middle. The minor premise, however, which specifically refers to objects in space and time appearances , is committed to an empirical use of the term. Indeed, such an empirical use would have to be deployed, if the conclusion is to be reached.

The conclusion is that the entire series of all conditions of appearances is actually given. In the dynamical antinomies, Kant changes his strategy somewhat. Rather than arguing as in the mathematical antinomies that both conclusions are false , Kant suggests that both sides to the dispute might turn out to be correct. This option is available here, and not in the two mathematical antinomies, because the proponents of the thesis arguments are not committing themselves solely to claims about spatio-temporal objects.

In the third antinomy, the thesis contends that in addition to mechanistic causality, we must posit some first uncaused causal power Transcendental Freedom , while the antithesis denies anything but mechanistic causality. Here, then, the debate is the standard though in this case, the specifically cosmological dispute between freedom and determinism.

Finally, in the fourth antinomy, the requirement for a necessary being is pitted against its opposite. The thesis position argues for a necessary being, whereas the antithesis denies that there is any such being. In both cases the thesis opts for a position that is abstracted from the spatio-temporal framework, and thus adopts the broadly Platonic view. The rational necessity of postulating such a necessary being or a causality of freedom satisfies the rational demand for intelligible explanation.

Insofar as the antithesis denies the justification for doing this, of course, it is said to adopt a broadly Epicurean standpoint. If space and time were things in themselves, then of course the application of the demand for this unconditioned would be warranted. Sign in via your Institution Sign in. Purchase Subscription prices and ordering for this journal Short-term Access To purchase short term access, please sign in to your Oxford Academic account above.

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Related articles in Google Scholar. Citing articles via Google Scholar. 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?

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, 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.

Other A-theorists, like Sullivan , hold that the present is metaphysically privileged but deny that there is any ontological difference between the past, present, and future. More generally, A-theorists often incorporate strategies from modal metaphysics into their theories about the relation of the past and the future to the present.

According to B-theories of time, the only fundamental distinction we should draw is that some events and times are earlier or later relative to others. According to the B-theorists, there is no objective passage of time, or at least not in the sense of time passing from future to present and from present to past. B-theorists typically maintain that all past and future times are real in the same sense in which the present time is real—the present is in no sense metaphysically privileged.

It is also true, and less often remarked on, that space raises philosophical questions that have no temporal analogues—or at least no obvious and uncontroversial analogues. Why, for example, does space have three dimensions and not four or seven? On the face of it, time is essentially one-dimensional and space is not essentially three-dimensional. It also seems that the metaphysical problems about space that have no temporal analogues depend on the fact that space, unlike time, has more than one dimension.

For example, consider the problem of incongruent counterparts: those who think space is a mere system of relations struggled to explain our intuition that we could distinguish a world containing only a left hand from a world containing only a right hand. So it seems there is an intuitive orientation to objects in space itself.

It is less clear whether the problems about time that have no spatial analogues are connected with the one-dimensionality of time.

Finally, one can raise questions about whether space and time are real at all—and, if they are real, to what extent so to speak they are real. Or was McTaggart's position the right one: that space and time are wholly unreal? If these problems about space and time belong to metaphysics only in the post-Medieval sense, they are nevertheless closely related to questions about first causes and universals.

First causes are generally thought by those who believe in them to be eternal and non-local. God, for example—both the impersonal God of Aristotle and the personal God of Medieval Christian, Jewish, and Muslim philosophy—is generally said to be eternal, and the personal God is said to be omnipresent.

To say that God is eternal is to say either that he is everlasting or that he is somehow outside time. And this raises the metaphysical question of whether it is possible for there to be a being—not a universal or an abstract object of some other sort, but an active substance—that is everlasting or non-temporal.

An omnipresent being is a being that does not occupy any region of space not even the whole of it, as the luminiferous ether of nineteenth-century physics would if it existed , and whose causal influence is nevertheless equally present in every region of space unlike universals, to which the concept of causality does not apply.

The doctrine of divine omnipresence raises the metaphysical question whether it is possible for there to be a being with this feature. But it is doubtful whether this is a position that is possible for a metaphysician who says that a white thing is a bundle composed of whiteness and various other universals. All theories of universals, therefore, raise questions about how things in various ontological categories are related to space.

And all these questions have temporal analogues. Related to questions about the nature of space and time are questions about the nature of objects that take up space or persist through time, and these questions form yet another central theme in post-medieval metaphysics. Are some or all objects composed of proper parts? Can more that one object be located in exactly the same region? Do objects persist through change by having temporal parts? Much work on persistence and constitution has focused on efforts to address a closely knit family of puzzles—the puzzles of coincidence.

Consider a gold statue. Many metaphysicians contend that there is at least one material object that is spatially co-extensive with the statue, a lump of gold. This is easily shown, they say, by an appeal to Leibniz's Law the principle of the non-identity of discernibles.

There is a statue here and there is a lump of gold here, and—if the causal story of the statue's coming to be is of the usual sort—the lump of gold existed before the statue. Or so these metaphysicians conclude. But it has seemed to other metaphysicians that this conclusion is absurd, for it is absurd to suppose these others say that there could be spatially coincident physical objects that share all their momentary non-modal properties.

Hence, the problem: What, if anything, is the flaw in the argument for the non-identity of the statue and the lump? Tibbles is a cat. Suppose Tail is cut off—or, better, annihilated. Tibbles still exists, for a cat can survive the loss of its tail. But what will be the relation between Tib and Tibbles?

Can it be identity? No, that is ruled out by the non-identity of discernibles, for Tibbles will have become smaller and Tib will remain the same size. But then, once again, we seem to have a case of spatially coincident material objects that share their momentary non-modal properties. Both these constitution problems turn on questions about the identities of spatially coincident objects—and, indeed, of objects that share all their proper parts.

A third famous problem of material constitution—the problem of the Ship of Theseus—raises questions of a different sort. Baker is a defense of this thesis. Others contend that all the relations between the objects that figure in both problems can be fully analyzed in terms of parthood and identity. For a more thorough overview of the solutions to these puzzles and different theories of constitution in play, see Rea ed.

Of course, discussion of causes go back to Ancient Philosophy, featuring prominently in Aristotle's Metaphysics and Physics. Aristotle classifies four such explanatory conditions—an object's form, matter, efficient cause, and teleology. An object's efficient cause is the cause which explains change or motion in an object.

With the rise of modern physics in the seventeenth century, interest in efficient causal relations became acute, and it remains so today. And when contemporary philosophers discuss problems of causation, they typically mean this sense.

One major issue in the metaphysics of causation concerns specifying the relata of causal relations. Consider a mundane claim: an iceberg caused the Titanic to sink. Does the causal relation hold between two events: the event of the ship hitting the iceberg and the event of the ship sinking? Or does it hold between two sets of states of affairs?

Or does it hold between two substances, the iceberg and the ship? Must causal relations be triadic or otherwise poly-adic? And can absences feature in causal relations? For example, does it make sense to claim that a lack of lifeboats was the cause of a third-class passenger's death? We might further ask whether causal relations are objective and irreducible features of reality.

Hume famously doubted this, theorizing that our observations of causation were nothing more than observations of constant conjunction. For example, perhaps we think icebergs cause ships to sink only because we always observe ship-sinking events occurring after iceberg-hitting events and not because there is a real causal relation that holds between icebergs and foundering ships. Contemporary metaphysicians have been attracted to other kinds of reductive treatments of causation.

Some—like Stalnaker and Lewis—have argued that causal relations should be understood in terms of counterfactual dependencies Stalnaker and Lewis For example, an iceberg's striking the ship caused its sinking at time t if and only if in the nearest possible worlds where the iceberg did not strike the ship at time t , the ship did not sink.

Others have argued that causal relations should be understood in terms of instantiations of laws of nature. Davidson and Armstrong each defend this view albeit in different ways. All of these theories expand on an idea from Hume's Treatise in attempting to reduce causation to different or more fundamental categories.

For a more complete survey of recent theories of causation, see Paul and Hall Debates about causation and laws of nature further give rise to a related set of pressing philosophical questions—questions of freedom. In the seventeenth century, celestial mechanics gave philosophers a certain picture of a way the world might be: it might be a world whose future states were entirely determined by the past and the laws of nature of which Newton's laws of motion and law of universal gravitation served as paradigms.

The problem of free will can be stated as a dilemma. If determinism is true, there is only one physically possible future. But then how can anyone ever have acted otherwise? But if determinism does not hold, if there are alternative physically possible futures, then which one comes to pass must be a mere matter of chance. Unless there is something wrong with one of these two arguments, the argument for the incompatibility of free will and determinism or the argument for the incompatibility of free will and the falsity of determinism, free will is impossible.

The problem of free will may be identified with the problem of discovering whether free will is possible—and, if free will is possible, the problem of giving an account of free will that displays an error in one of or both these arguments. Van Inwagen defends the position that, although the modern problem of free will has its origin in philosophical reflections on the consequences of supposing the physical universe to be governed by deterministic laws, the problem cannot be evaded by embracing a metaphysic like dualism or idealism that supposes that agents are immaterial or non-physical.

If it is natural both to pair and to oppose time and space, it is also natural to pair and to oppose the mental and the physical. The modern identity theory holds that all mental events or states are a special sort of physical event or state. The theory is parsimonious among its other virtues but we nevertheless exhibit a natural tendency to distinguish the mental and the physical.

Perhaps the reason for this is epistemological: whether our thoughts and sensations are physical or not, the kind of awareness we have of them is of a radically different sort from the kind of awareness we have of the flight of a bird or of a flowing stream, and it seems to be natural to infer that the objects of the one sort of awareness are radically different from the objects of the other. That the inference is logically invalid is as is so often the case no barrier to its being made. Whatever the reason may be, philosophers have generally but not universally supposed that the world of concrete particulars can be divided into two very different realms, the mental and the material.

If one takes this view of things, one faces philosophical problems that modern philosophy has assigned to metaphysics. Prominent among these is the problem of accounting for mental causation. If thoughts and sensations belong to an immaterial or non-physical portion of reality—if, for example, they are changes in immaterial or non-physical substances—how can they have effects in the physical world?

How, for example, can a decision or act of will cause a movement of a human body? How, for that matter, can changes in the physical world have effects in the non-physical part of reality? If one's feeling pain is a non-physical event, how can a physical injury to one's body cause one to feel pain?

But the former has troubled them more, since modern physics is founded on principles that assert the conservation of various physical quantities. If a non-physical event causes a change in the physical world—dualists are repeatedly asked—does that not imply that physical quantities like energy or momentum fail to be conserved in any physically closed causal system in which that change occurs? And does that not imply that every voluntary movement of a human body involves a violation of the laws of physics—that is to say, a miracle?

A wide range of metaphysical theories have been generated by the attempts of dualists to answer these questions. Some have been less than successful for reasons that are not of much intrinsic philosophical interest. Broad, for example, proposed — that the mind affects the body by momentarily changing the electrical resistance of certain synapses in the brain, thus diverting various current pulses, which literally follow the path of least resistance into paths other than those they would have taken.