The Practice of Synthesis

A look at Kant's transcendental philosophy as a contemplative discipline, showing how a priori structures and faculties can enable the cultivation of perception

Jul 11, 2025

The main elements of this piece on Immanuel Kant first came to life for a talk I give back in ~2019, and I’ve been looking for a way to develop them further ever since. This week, I had the opportunity to do so. Also, two pieces I recently published here — “Practice, Perception, and Being” and “Attention is First Philosophy” — finally made it clear to me what it is I wanted to do with Kant several years ago: to show how transcendental philosophy functions as a contemplative discipline concerned with the cultivation of the subject. The piece assumes some familiarity with the Critique of Pure Reason, but I’ve tried to lay out the terms as best I can for those new to the work. And, I’ll admit, it’s a bit technical, and a bit heterodox, but what good is the transcendental philosophy if you can’t raid it for parts in your own project?

This essay develops one dimension of a broader project I explored in “Practice, Perception, and Being: A Sequential Account,” where I argued that philosophical askēsis (meaning “exercise” or “discipline”) reshapes perception by transforming the horizon within which things appear.

Here, I focus on a particular thread of that account by showing how Immanuel Kant’s transcendental philosophy — that is, his philosophical inquiry into the conditions that make experience and knowledge possible — offers a rigorous articulation of the structures through which perception is formed, and how those structures, once examined, reveal the possibility of their deliberate reshaping through practice.

Pierre Hadot once remarked that “the entire edifice of critical Kantian philosophy has meaning only from the perspective of wisdom, or rather from that of the sage.” This might sound surprising, given Kant’s reputation for technical rigor and abstract method. But Hadot’s remark invites us to reconsider Kant as a philosopher concerned with the cultivation of the subject, rather than simply an architect of rational analysis.

What I want to show is that Kant’s critical philosophy offers a practice-oriented model of how perception is shaped (and reshaped) through the synthetic acts of attention, judgment, and imagination.

My leading question is the following: If the transcendental philosophy is true, how might we describe the cultivation of perception through practice within it?

My answer, outlined in more detail below, is the following:

The cultivation of perception occurs through the refinement of synthetic operations, those spontaneous acts by which the understanding coordinates with sensibility to unify experience. While Kant’s a priori structures (space, time, categories) remain universal and unchanging, the particular ways these structures get enacted in concrete synthesis varies from person to person. This spontaneity creates a space where, through deliberate practice, individuals can train how the manifold of intuitions gets organized and unified, enabling new subtleties and distinctions to emerge in experience. Transcendental philosophy in its common expressions suggests that perception is neither passive reception nor pure construction but synthesis. My wager is that this synthetic construction is what gets transformed through active practice and cultivation within the framework of universal cognitive conditions.

1. Kant’s Method and the Structure of Attention

We can see how this practical reading of perception begins to take shape in Kant’s own terms by considering how two of his translators, Paul Guyer and Allen W. Wood, describe his method of philosophy:

This new science, which Kant calls “transcendental” (A11/B25), does not deal directly with objects of empirical cognition, but investigates the conditions of possibility of our experience of them by examining the mental capacities that are required for us to have any cognition of objects at all.

Kant’s central move, we could say, is to shift our attention from what we experience to how we come to have experience in the first place. Experience in this sense is actively constructed, rather than passively received, through the coordinated activity of our cognitive faculties.

What transcendental philosophy offers, then, is a rigorous inquiry into the enabling conditions of appearance itself. This is not typically described as a contemplative or ascetical practice, but I want to propose that it can be interpreted as such. What Kant gives us through the critical or transcendental philosophy is a method of turning thought back onto the structures that shape its own access to the world.

In this sense, transcendental philosophy becomes a kind of disciplined self-examination — not as a psychological act, but as a structural and formal one — through which we gain insight into the capacities that make perception, judgment, and moral action possible. Kant’s project can in this way be read as a modern response to the ancient imperative gnōthi seauton (“know thyself”), reconfigured here in a transcendental key. It is this interior redirection that allows me to draw the connection to askēsis and contemplative practice.

In a related essay, I explored how attention also plays a formative role in the philosophies of Aristotle, Descartes, and Merleau-Ponty, each of whom begins, I argued, with a reorientation of perception that reshapes the conditions under which philosophical questions arise. Kant’s transcendental project differs from these approaches in that it does not take attention as a starting point in the order of being or explanation, but it may well begin there in the order of inquiry.

For Kant, what prompts critical philosophy is reflection on the conditions of experience, of which attention is a part, but this leads to the discovery that even our capacity to attend is conditioned by deeper, a priori structures.

Central among these structures is the transcendental unity of apperception (the mind’s formal capacity to be self-aware across all representations), which Kant describes as the necessary condition for the possibility of coherent experience. It is the form of self-consciousness that must accompany all representations (“the ‘I think’ that must be able to accompany all my representations”), serving as the unifying thread that binds the manifold of intuition into a single, knowable experience.

This is why I suggest that Kant’s transcendental philosophy can be read as a kind of contemplative or ascetical practice, one that teaches us how to perceive the manifold of intuition in a new way — as the structured multiplicity of appearances given in sensibility (in space and time) — which must be synthesized and unified by the understanding in order to constitute coherent experience.

This unity is not empirical, but transcendental. In other words, it does not describe a particular psychological state, but the formal condition that makes cognition possible at all. While Kant does not use the term “attention” here, we might say that attention already presupposes this unified field made possible by apperception.

Thus, while attention is not foundational in Kant’s system qua system, it becomes one of the phenomena that initiates and orients the transcendental investigation. And in turning back to investigate its own conditions, transcendental philosophy requires a kind of methodological attentiveness, one that bears affinities to contemplative or ascetical practices, even if Kant himself does not frame it that way.

2. Askēsis and the Architecture of Cognition

From this angle, Kant’s project can be interpreted as a form of philosophical askēsis. Not a regimen of bodily austerity per se, but a kind of intellectual or spiritual exercise aimed at clarifying the forms through which appearances come to be seen and known.

What he offers is a discipline for tracing how cognition synthesizes the manifold of experience under concepts, and how the faculties of sensibility, understanding, and imagination coordinate to generate objective appearance. This synthesis is not freely willed, but governed by conditions that transcend any particular act of perception.

And while Kant emphasizes that these operations occur spontaneously and often pre-reflectively, I want to suggest that they are not beyond the reach of cultivation. If the synthesis that gives rise to experience can be brought into reflective examination, it can also become an object of intentional practice, a space in which perception itself can be trained, deepened, and reoriented.

In other words, Kant was highlighting that the type of experience one is capable of having is related to the structures or capacities of the person having the experience. Kant’s philosophy is in this way a contemplative approach to the workings of the mind and its structures. These are some of the links we might elucidate between askēsis, contemplation, and transcendental philosophy.

What I am doing here is pointing to structures, practices, and faculties available to transcendental reflection. The value of what I am saying isn’t secured by argument alone, but by the reflective investigation that reveals these philosophical operations within experience itself.

This attitude of foregrounding askēsis in a practical and transcendental mode sets up what I think can serve as a general account of the relation between askēsis and perception, an account that has as one of its features the particularity of your own concrete situation. That said, I will give you what I think is a coherent argument for the relation between askēsis and perception, and it starts with a few of the resources we get from Kant’s transcendental philosophy.

One of Kant’s most important metaphors is what he calls the Copernican Revolution in philosophy. Rather than assuming that our cognition must conform to the world, he proposes we explore what happens when we suppose that the world must conform to the structures of our cognition. This reversal relocates the task of metaphysics: no longer concerned with speculation about things-in-themselves, we instead investigate the transcendental conditions under which objects can appear to us at all.

In doing so, Kant doesn’t claim that we create the world, but that the world must be rendered intelligible through the structures of our mind, and specifically, through the interplay of intuition and concept. Now, we don’t have time to explore every element of this reversal, so I just want to focus in on a few paragraphs in The Critique of Pure Reason where he argues there are two basic sources for our cognition, sensibility and understanding. Here’s Kant in his own words:

Our cognition arises from two fundamental sources in the mind, the first of which is the reception of representations (the receptivity of impressions), the second the faculty for cognizing an object by means of these representations (spontaneity of concepts); through the former an object is given to us, through the latter it is thought in relation to that representation (as a mere determination of the mind). Intuition and concepts therefore constitute the elements of all our cognition, so that neither concepts without intuition corresponding to them in some way nor intuition without concepts can yield a cognition. (A50/B74)

For Kant, sensibility and understanding come together in each moment of cognition, but as our two basic faculties they involve two different types of content. The understanding is conceptual, discursive, and involves thought. Sensibility involves intuitions, sense perception, and images. In other words, it gives the sheer presence of something, in a moment of givenness, prior to reflection.

The understanding then takes up this givenness and organizes it discursively, forming a rule or concept through which what appears can be thought. To put it another way: intuition delivers the immediate presence of something in space and time, while the understanding interprets and subsumes that presence under a rule, as a way of making it intelligible.

Those of you familiar with this system will know that a concept is a general, universal representation expressed discursively — it is a way of placing a thing into a category — while an intuition is immediate, object-dependent, and externally caused. It is, roughly speaking, a sense impression entering cognition from the outside, a way of being responsive to the particularity of your environment.

And importantly, Kant identifies space and time as the pure forms of intuition, the a priori conditions that structure all our empirical intuitions. Space governs the form of outer sense, time the form of inner sense. Space and time, for Kant, are a priori forms not learned through experience, but given in advance as the necessary conditions that structure all possible intuitions. These are not derived from experience, but are the conditions that make experience possible in the first place.

One further feature I want to highlight here is that both concepts and intuitions execute automatically. This is we could say a pre-conscious process, so that whatever it is that shows up for you in awareness has already been through this process of semantic organization. This automaticity — the fact that much of this synthesis occurs pre-reflectively — is key to Kant’s notion of judgment.

Judgment, for Kant, isn’t an explicit deliberative act in the way normally think of “judgments”; it’s the spontaneous organization of what is sensed into something that can be experienced as an object, the very act of bringing the objects of experience into your awareness as those objects, and this involves the act of synthesizing the qualities, properties, and relations that we take to be essential to the objects we experience.

This synthesis is what allows disparate sensations to appear unified, coherent, and meaningful. This act of unification both renders perception intelligible, and it shapes the perceptual horizon itself as that structured field within which appearing becomes possible. In this light, Kant’s system aligns with a broader view in which appearing is always conditioned by what the perceiver brings to the encounter.

My secondary question here is: If the synthesis that structures perception is open to examination, can it also be cultivated?

I think we can say, yes, but we need to lay out few more details to describe, exactly, how and where this cultivation takes place. To do that, we need to understand the basic shape of synthesis itself, including how it operates, and what it gathers together.

3. The Manifold and the Task of Synthesis

“The manifold,” in Kant’s sense, refers to the multiplicity of intuitions that must be synthesized in each moment of cognition.

The manifold is all of the given intuitions synthesized in a specific scenario as coordinated with the understanding, or its taking of the manifold to be in a certain way. This synthesis is an active mode of combination made possible by what Kant calls the productive imagination, a faculty that bridges sensibility and understanding.

It allows intuitions to be held together across time and recognized as belonging to an object. Without this faculty, experience wouldn’t have the unity required to yield knowledge. Perception, then, is a composition performed by the person, and this performance, I am suggesting, is precisely what’s made changeable through practice.

So, just to review our terms, we’re talking about two sources of cognition — sensibility and understanding — that come together in each moment of perception and this coming together involves a judgment, which means something like taking a stance, automatically and pre-reflectively, about what is currently being rendered in your perception; it’s about fashioning mental representations of what’s being delivered to the understanding through sensibility.

The key here is that at least some of this process involves spontaneity, which means that even within Kant’s universal transcendental framework, the concrete enactment of synthesis varies from person to person. This spontaneity creates a space where, though the basic structures remain constant, the particular ways they synthesize experience can be refined through practice, and this requires our active participation, and opens our perception to certain degrees of freedom.

I won’t dwell too far into the details here, but some Kant scholars, like Henry Allison, argue that spontaneity occurs only on the side of the understanding, while others, like Thomas Land, believe that spontaneity exists both in the mode of sensibility and the understanding. This debate over spontaneity, whether it belongs exclusively to the understanding or extends into sensibility itself, has important consequences.

Such training involves shaping the horizon within which experience arises, of cultivating the background conditions that govern what appears, how it appears, and to whom. The dynamic structure of this horizon allows for its gradual transformation through practice. If the faculty of sensibility can be shaped, then perception is not fixed or passive reception alone (and so the same for everyone) but can be trained, refined, and redirected.

In this light, attention itself might be understood as a kind of spontaneous focus, suggesting that askēsis involves more than just interpretive discipline; it reaches into the very ways we are affected by the world. Along these lines, I am inclined to agree with Thomas Land, as it seems that even what we think of as physiological sense impressions are open to creative reconstruction, refashioning, and redirection (cf. the cognitive science literature on perceptual learning).

It also makes sense of why ascetic practices, including nondiscursive or nonverbal activities, seem able to deliver not just a reorientation of the senses, but also a reorientation of the understanding.

What Kant begins to offer us here is a philosophy in which perception is neither a passive reception nor a pure construction, but something practiced, shaped, and cultivated. In that light, transcendental philosophy gives us a few very specific handholds that we might grip through the discipline of attention.

4. On Conformation and the Shaping of Perception

I often return to these passages in Kant because they seem to describe, in a technical key, the structure of what later comes to be called phenomenological intentionality. Along these lines, I’ve come to think of skilled intentionality as a kind of practiced conformation, a training of the manifold of perception and intuition to bend in certain ways on purpose.

I can now restate my thesis in the following way: practices of conformation, in Kant’s sense of “objects conforming to cognition,” are ways of reshaping how the manifold gets synthesized. To take up a concept in experience is to reshape how the manifold gets unified, so that new details, emphases, and affordances for action are revealed.

Contemporary research on perceptual learning provides evidence for the kind of synthetic cultivation that Kant’s system makes theoretically possible. For example, botanical expertise retrains how the manifold gets organized through practice. The manifold of visual intuitions that constitutes a forest walk becomes synthesized differently as expertise develops: ecological relationships and species distinctions emerge from what was previously undifferentiated visual content.

This transformation occurs through the cultivation of synthetic operations, the spontaneous acts through which the understanding coordinates with sensibility to unify experience. What cognitive science documents about perception is actually this cultivation of synthetic operations that Kant described, supporting what his transcendental analysis predicted—that the synthetic processes constituting experience, while governed by universal conditions, remain open to deliberate cultivation through practice.

But the concept is only one means of reshaping the synthetic process.

Practices of all kinds, many of them nondiscursive, can reorganize experience. For example, contemplative practices train attention to synthesize temporal experience differently, allowing the manifold of inner awareness to be unified in ways that disclose subtleties of consciousness previously unavailable to experience. They, too, reshape the synthetic process through the cultivation of how the productive imagination coordinates sensibility and understanding.

If we can see the link between Kant’s manifold of intuition and its capacity to be shaped through practice, we can begin to understand spiritual, contemplative, and even artistic exercises in a new light, as ways of shaping and reshaping the person within the space opened up by transcendental philosophy.

This shaping of perception is what connects the disciplines I draw from.

It allows us to understand science, philosophy, the arts, and religious traditions not as competing doctrines alone but as shared practices of perceptual transformation. In that sense, this essay complements the more general account developed in “Practice, Perception, and Being,” showing in Kant’s philosophy a concrete model of how attention, shaped by practice, reorganizes the very possibility of appearing.

I think in the final analysis we can say that this reading of Kant reveals transcendental philosophy as fundamentally concerned with the cultivation of perception itself.

By showing how the spontaneity inherent in synthetic operations creates space for deliberate practice within universal transcendental structures, we see that Kant’s critical philosophy provides a framework for understanding how it can be systematically refined. The transcendental conditions that govern cognition do not fix perception in place but rather establish the ground upon which perceptual cultivation becomes possible.

Transcendental philosophy emerges here as both an analysis of the structures of experience and as an opening for their deliberate transformation through askēsis.