Philosophy is, no doubt, the slowest-moving branch of human inquiry. The best proof of this can be seen in its peculiar use of the word “modern.”

When musicians speak of “modern jazz,” they are generally referring to the emergence of bop in the 1940s, as in the music of Charlie Parker and Dizzy Gillespie, and thus to a period of music that is still honored today even if supplanted by later developments. Modern architecture looks further back in time, to the early twentieth century rejection of the Beaux Art and Neoclassical styles. Although modern architecture still produces original variants even now, there would be an inherent challenge in arguing that “modernism” is still an accurate description of that field today. Modern art goes back even further, and is often traced to Édouard Manet’s canvases of 1863. Here, there is wider consensus that modernism is dead, replaced by a “postmodern” period identified as running from the 1960s through the present.

Is modern philosophy a thing of the past, in the way that one might argue for modern jazz, modern architecture, and modern painting? It may be surprising for readers to learn that “modern philosophy” is taken to begin with René Descartes (1596-1650), who abandoned traditional Arisotelianism in favor of regrounding the discipline in the immediate evidence of the thinking human subject: “I think, therefore I am.” A nuance is usually added: Descartes and his fellow seventeenth-century thinkers are often qualified as “early moderns,” while modern philosophy proper (the kind that is still practiced today) is defined temporally by the ideas of the Scottish skeptic David Hume (1711-1776) and the pivotal German thinker Immanuel Kant (1724-1804). No philosopher is likely to be taken seriously if they attempt to return to the period prior to Hume. A case in point is the twentieth-century English philosopher Alfred North Whitehead (1861-1947), who, while widely respected as a mathematician, is not universally recognized as part of the canon of great philosophers. The reason for this can be found largely in his rejection of the basic presuppositions of the Hume/Kant modernism. By and large, those who wish to be taken seriously in academic departments of philosophy need to accept these presuppositions.

This article takes a contrary view. As I see it, we are long overdue for a revision of what counts as an acceptable starting point for philosophy, and, therefore, for a decisive parting with modernism, which the other fields mentioned above completed as long as half a century ago.

The reason for Descartes’ famous principle (“I think, therefore I am”) was his wish to ground philosophy in a rigorous starting point worthy of mathematics or the natural sciences. To do this, he undertook his famous method of radical doubt. Am I really so sure that I am not dreaming or deluded at this very moment? This question has become the basis of much that popular culture considers “philosophical”: in films ranging from The Wizard of Oz to Fight Club to The Matrix, the philosophically minded director is thought to be one who challenges our commonsense notion of reality, to the point that this has become a cliché: “it was all just a dream.” But the science fiction writer J.G. Ballard claimed the opposite: given that we are now surrounded with fictions in everyday life (propaganda, advertisements, conspiracy theories) the role of the artist has been reversed, and should now involve creating realities able to hold together the many fictions that perplex us.

In any case, Descartes asks us to imagine the worst-case scenario of an evil God who deceives us about absolutely everything, so that even my body and the facts of my everyday life are “fake news.” But even under this nightmare scenario, Descartes held, I must still be thinking in order to be deceived. If I did not at least exist as a thinker, the evil God would have had no one to deceive. Therefore, to repeat: “I think, therefore I am.” From there, Descartes provides further arguments that strike most contemporary readers as more naïve, and, therefore, as not fully modern (but just “early modern”) whereas Hume and Kant can still be called modern in the full-fledged sense. Namely, Descartes said that since I have an idea of perfection in my mind but no experience of anything perfect, the idea of perfection must have been put in my mind from the outside. This must have been done by a perfect God, who (since He is perfect) could not be deceiving us constantly, and, as a result, we cannot be experiencing a world of sheer illusion. We do make many errors, of course, but for Descartes these errors result only from an improper use of our reasoning powers. If we use our reason correctly, the truth is well within our grasp. Aside from his philosophical work, Descartes was also a pioneer in the use of mathematical reasoning in physics, and is a key figure in the scientific revolution no less than in modern philosophy itself.

Hume and Kant strike us as more fully modern because they do not resort to the argument from God, but base their philosophies on the evidence of immediate experience. For Hume, all we see in experience are perceptions, qualities, or ideas, not objects. The apple sitting before me need not be an independent object called an “apple,” since all we really experiences are its shifting qualities: red, ripe, spherical, shiny, and so forth. In other words, the apple is just a “bundle of qualities” rather than an object, and by analogy, what I take to be my mind is really just a “bundle of perceptions” with no evidence of an identical “soul” or even “mind” that persists from birth to death and beyond. By the same token, we have no evidence of causal relations between things outside the mind. Although it seems as if every time we touch fire it burns and hurts us—meaning that we would do well never to put our hands in fire—, there is no way to prove that the next time we touch fire it will not freeze us instead. All we have is experience. Enduring objects, our own enduring minds, and the apparent causal powers of both, are known only from experience and cannot be established as existing outside it.

Kant wrote that Hume’s writings awoke him “from his dogmatic slumber.” Hume, he held, was basically right, but with disastrous consequences for human knowledge. Accordingly, Kant created a famous divide between what he called the thing-in-itself (the real world outside us) and appearances (the world as it seems in experience). Although he agreed with Hume that we could never prove the existence of individual objects or souls, let alone causal relations outside human experience, he denied that knowledge of such things was impossible. Instead, we merely need to accept that no knowledge is possible of the thing-in-itself outside experience, but that knowledge can be attained of the unvarying structures of human experience itself. Examples of such structures include the fact that time moves in one direction from past to future, that space is experienced as having exactly three dimensions, and that human understanding functions according to twelve “categories” which are so basic that we cannot even imagine a kind of experience that would not follow them. For Kant, cause and effect is one of these categories: perhaps in the world of the thing-in-itself things happen randomly, or do not happen at all, but for human experience it is an absolute law that everything happens according to a law of cause and effect.

Now, philosophers since then have by no means accepted everything said by these two thinkers. Many do not accept Hume’s notion that mathematics deals with logic alone, and practically no one accepts Kant’s idea of a thing-in-itself beyond all human experience. Nonetheless, Hume and Kant still feel like contemporaries, because nearly every self-respecting philosopher accepts the two pillars of philosophy borrowed from them.

I call these pillars “Taxonomical.” Usually, taxonomy refers to the classification of the various types of anything that exists: the numerous kinds of birds, fish, or berries there are in the world. But Taxonomy is very simple in the case of modern philosophy, which recognizes two, and only two, kinds of things: (1) human thought, and (2) everything else. While this may look absurd at first glance –why should a fragile and recent animal species like human beings deserve to fill up half of philosophy?– we recall that Descartes gave what looked like a good reason for it. Namely, human thought is immediately given to me and must exist, since otherwise I cannot even be dreaming or hallucinating, while everything else (including God and the world) is only known derivatively by comparison with thought.

In short, Modern Taxonomy can be rewritten as: (1) that which is immediately given, and (2) that which is known only in mediated fashion. This gave rise to what might be called the intellectual division of labor in the modern world, in which philosophy is left to puzzle over the thought-world relation, while the relation between any two parts of the world itself is reserved for natural science.

This, in turn, leads us to another variant of Modern Taxonomy: (1) restriction of philosophy to the thought-world relation, and (2) science-worship when it comes to the relation between inanimate objects. By “science-worship” I mean something very specific: the notion that in treating topics such as causality, time, space, and individuals, philosophy must not stray far from the current state of “the best science we have.” We saw that Hume and Kant set the general horizon for what counts as respectable philosophizing today. The best way to look like a philosophical crackpot is to reject one or both pillars of Modern Taxonomy: if you say that we can think about the features belonging to all relations and not just that between thought and world, or if you claim that philosophy has nothing to add about “nature” that the natural sciences are not already saying better, you are likely to look suspicious, even if you are as great a speculative thinker as Whitehead himself. In this spirit, and returning to the title of this article, what would the end of modern philosophy look like? It would amount to the end of the two pillars of Taxonomy: (1) philosophy is primarily concerned with the relation between world and thought, and (2) science-worship as concerns the relation between anything in the world outside thought. If we reject these two principles, have we not automatically become pre-modern crackpots? Not at all. Let’s take them one at a time.

The idea that philosophy is (at least initially) trapped in the sphere of thought has been called the “correlational circle” by the French philosopher Quentin Meillassoux, who accepts this circle as his starting point. We cannot think a thing outside thought (or so the story goes) because this itself is a thought, and, therefore, we have already contradicted ourselves. This argument recurs frequently. It was the basis for the German Idealists’ rejection of Kant’s thing-in-itself outside thought, and much later it was used by Jacques Derrida to say that there could not be an absolute otherness outside appearance, since otherwise we would never have thought of it. But the argument is not as powerful as it looks.

While it may be a truism that I experience nothing but what I experience, to think that there might be something outside experience is not self-contradictory. All thoughts are thoughts, but thought need not be limited to what presents itself directly to thought. More importantly, the idea that something might exceed thought is called “human finitude,” but such finitude is deduced rather than something I experience directly. This is already obvious when we turn to consider the experience of other humans. I have never been my wife or my boss, and so I cannot know exactly what their experience is like. But I still deduce that they are finite just like I am: that they, too, experience the world in a way that might not be identical with the way the world really is. We can make the same inference about animal experience: a bear or eagle, because they are specific creatures with specific mentalities, also experience the world in their own way, even if we cannot actually be a bear or eagle and see for ourselves. The same must be true of plants and fungi, which interact with the world in their own way, even if it differs from that of “conscious” animals in ways that are not entirely clear. Finally, we can even deduce that inanimate objects encounter the world in a specific and limited way, even if we assume (though many do not) that such objects are not conscious at all.

In short, the modern philosophical assumption that we can only speak about the human relation to the world is false. While it may be more difficult in practice to imagine how a fish or mushroom confronts the world than how other humans do, we can still make certain deductions about finitude that apply far beyond the human realm. In this way, the first pillar of Modern Taxonomy collapses.

As for the notion that only science is allowed to discuss the realm of inanimate objects, we can perfectly well accept the vast importance of the scientific revolution to human flourishing, without, however, conceding that philosophy and other fields have nothing to add. Science conceptualizes inanimate entities according to their properties in space and time, which means entities in their relations to other things. Yet, there is no good reason to think that describing things in terms of their relations exhausts what those entities are. Things must have a surplus over and above their current relations if we are to have any way to explain how things react unexpectedly in different situations: a theory called “scientific realism.” If the philosophical problems concerning finitude go beyond the relational conception, then science cannot exhaust the reality of inanimate things, however powerful its relational results may be. Thus, the second pillar of Modern Taxonomy also falls and the signs of a near end of modern philosophy become hard to ignore.