Video transcription

For Kant, knowledge arises from the encounter between two functions of our cognitive apparatus: Sensibility and the Understanding.

At first there is a sensory encounter with the Phenomenon, that is, with what appears before us. This initial material is a stream of data not yet organized, sheer impression. To become knowledge, that stream must be ordered and unified according to rules—and those rules are determined by the Understanding.

From the processing of sensible material, there arise Empirical Concepts, that is, general representations obtained by comparing many perceptions and abstracting what they have in common. Thus, for example, from the perception of a multiplicity of individuals, the mind is able to form the Empirical Concept of 'man'.

Alongside these Empirical Concepts, Kant posits the Pure Concepts of the Understanding. They do not arise from sensible perceptions, but rather precede experience, and for this reason are called 'a priori'. They are not images derived from the senses: they are functions, or forms, of thinking, by virtue of which the manifold of experience can be unified under rules and thus become objective knowledge.

These Pure Concepts are limited in number, and Kant gathers them into the celebrated Tables, of which we shall speak later.

Our basic thesis is that the path by which Kant deduces the Pure Concepts ends up isolating, in the form of a functional list, the very same structures that, in our reading, correspond to the Pythagorean and Platonic Forms expressed through an archetypal diagram.

However, since the Aristotelian tradition had construed Platonic Forms as constituents of a “new ontology”, thereby generating pseudo-metaphysics, Kant seeks to rid himself of this cumbersome legacy and to begin again from first principles in his inquiry into the formal conditions of knowledge.

The connection between Pure Concepts and Forms will be argued in detail in the chapter devoted to the reconstruction of the diagram.

In the previous video, we recounted Kant's project, namely, to refound Metaphysics, a discipline that for him coincides with Philosophy in its highest sense. If it is to aspire to genuine science, the new Metaphysics must renounce an ancient pretension: to speak as though it could directly know the so-called 'Intelligible World'.

Kant does not maintain that such a world does not exist; he claims, instead, that—with our limited means—we cannot know it:

“From the earliest age of Philosophy, speculative philosophers have admitted, besides sensible beings or 'Phenomena', which constitute the Sensible World, certain particular intelligible entities, 'Noumena', which would ground the Intelligible World.

Since such philosophers believed that the 'Phenomenon' and 'illusory appearance' were the same thing, they were led to attribute 'true reality' only to intelligible entities.

When we rightly regard the object of the senses as mere 'Phenomena', as appearances, we are implicitly admitting that these Phenomena have, as their ground, a 'thing in itself', although it is not given to us to know it as it is 'in itself', since we can know only the Phenomenon, that is, the manner in which this unknown object affects our senses.

The mind, therefore, by the very fact that it admits Phenomena, is compelled also to admit the existence of 'things in themselves'. We may say that the representation of those entities which ground Phenomena, that is, the representation of pure intelligible entities, is not only legitimate, but inevitable.

Our critical deduction by no means excludes such intelligible entities, but it does so with a rigorous and unassailable restriction, namely, that we do not know, nor can we ever know, anything concrete about such intelligible entities, because our Pure Concepts and our pure intuitions refer exclusively to objects of possible experience, and therefore only to sensible entities.

As soon as one abandons sensible entities, intelligible entities lose sense and value.”

Kant, then, does not deny that there may exist something transcendent that grounds the Phenomenon. He says, rather, that even if it existed, and he does not rule it out, we could not know it directly. We may name it; we may even feel compelled to admit it as a presupposition. Yet without an anchorage in experience, every hypothesis remains a mere conjecture, devoid of objective confirmation.

Here Kant strikes at a precise target: the temptation to investigate the transcendent, as though it were an object within reach, simply located beyond experience. At that moment, the mind is not “discovering” anything: it is projecting its own forms outside itself, and then mistaking them for reality.

But what, precisely, does Kant imagine when he speaks of the 'Intelligible World'? In the language inherited from the post-Aristotelian tradition, what is called the 'Intelligible World' tends to be imagined as a reality alternative to the Sensible World. And if this is the dominant image, then Kant's critique appears inevitable.

Many metaphysical systems prior to him, conditioned by Theology, are fantastic constructions, impossible to verify and impossible to refute. To make Philosophy a science, Kant proposes a change of course: no longer a Metaphysics of the "transcendent", but a "transcendental" inquiry, that is, a rigorous study of the conditions that make experience possible and, with it, knowledge.

To use a metaphor, Kant shifts attention from the object placed before the mirror to the image that forms upon the mirror's surface, and to the 'laws of reflection' that produce that image.

For Kant, experience is not a 'given' to be grasped objectively: the given is structured by 'a priori' forms and by Pure Concepts that order sensible contents. Understanding the nature of these Forms is essential, because from them there arises a powerful illusion, a self-deception.

The mind takes these Pure Concepts and detaches them from their legitimate use, believing it can employ them to describe a world situated beyond experience:

“We must admit that our Pure Concepts insidiously drive us towards a transcendent use of them—'transcendent' in the sense that it oversteps all possible experience.

They drive us to this use, because our concepts of 'substance', 'force', 'action', 'reality', are independent of experience, containing no phenomenal element, and therefore they seem to us genuinely to refer to 'things in themselves', to 'Noumena'.”

The Pure Concepts our mind produces—such as 'substance', 'force', 'action', 'reality'—lead us to suppose that “something real” exists under these names, yet they are only the product of our mental activity, the categories through which we interpret the world:

“Pure Concepts seem to have a scope and a content far wider than they possess in their mere use within experience.

And thus the mind, without noticing it, constructs, alongside the construction of experience, another construction far greater, which it populates with Pure Concepts, without noticing that it has overstepped the limits of their use.”

While the use of these Pure Concepts can be useful in the scientific domain—for instance, in explaining physical laws—their use as “bricks” with which to build worlds alternative to the sensible one is, in fact, an improper use:

“When the mind gives itself over to fantasy, it begins, in an innocent and legitimate way, by imagining new 'powers of Nature' and ends by positing entities external to Nature.

In short, by constructing 'another world' which experience can neither confirm nor refute.

This is why young philosophers so often favour 'dogmatic metaphysics' and devote to it so much time and energy, which they might apply elsewhere.

So long as the illegitimacy of such metaphysical conjectures is not clearly demonstrated, and so long as the mind's knowledge of itself does not become a true science, rigorously distinguishing its legitimate use from its improper use, these attempts will never cease.”

We now reach the key point: what does Kant truly mean when he speaks of 'intelligible entities', of 'Noumena'? The concept arises from the previous philosophical debate, and carries with it an inevitable ambiguity.

On the one hand, the Noumenon is a limit, the sign that indicates where knowledge can go no further. On the other hand, the very presence of the term evokes “a something” situated beyond the Phenomenon, and precisely for that reason the mind spontaneously tends to treat it as a “pseudo-object”.

Kant does not intend to construct a “second world”, as does the dogmatic metaphysics that precedes him. And yet he leaves in the background a “residue”, a “beyond” that he declares 'unknowable', but which language tends to reify. The listener thus ends up inevitably imagining the Noumenon as a “thing behind the thing”, precisely what Kant would like to prevent.

It would have been possible to avoid this misunderstanding, in our view, only by clarifying the 'ideal' nature of the Noumenon, and declaring it knowable as pure 'Form'.

The Intelligible World of Pythagoras and Plato is not “another world” populated by pseudo-physical objects. It is a structure of logical Forms rendered visible, so to speak, by a diagram.

Kant, however, in his own time, still carries with him the metaphysical debate of the preceding centuries, already misled by the Aristotelian framework. Given his premises, what is Kant's plan for arresting the uncontrolled proliferation of metaphysical conjectures? A stringent criterion: to validate as 'knowledge' only what can find confirmation in experience.

His system proceeds in two moments: first, the sensible encounter with the Phenomenon; then, the organization of that material through forms and Pure Concepts. In short, the Senses supply the data; the Understanding determines their form.

And it is precisely in the search for, and elaboration of Pure Concepts that, according to our interpretation, Kant meets Plato without intending to. For when Kant deduces his Categories, he is not studying the product of a particular mind and its subjectivity: he is attempting to deduce 'formal constraints' that reside in a universal and objective dimension—a 'transcendent' dimension, precisely because it lies beyond the individual mind.

Indeed, the Pythagorean and Platonic Forms are nothing other than the much discussed 'conditions of possibility' of thought, as studied by the transcendental system. A 'condition of possibility', in fact, is nothing other than a 'formal constraint'.

The point of divergence from Plato is, however, the method. Kant insists on determining these conditions “from below”, starting from experience, because he denies that human beings possess an 'intellectual intuition'. He admits only a 'sensible intuition'. What we intuit, he holds, arises solely from the encounter with the Phenomenon:

“By means of Pure Concepts, one cannot think anything outside the domain of experience. They do nothing but determine the form of judgment in relation to given intuitions.

Since there are no intuitions beyond the field of sensibility, the Pure Concepts lack all objective validity because they cannot in any way be represented concretely.

To determine the Noumena that populate the Intelligible World is, therefore, for us, an impossible task, because our mind cannot intuit, but only connect the intuitions that come from experience.

Experience must contain all the objects corresponding to our concepts. Outside experience, every concept loses meaning, since the intuition that constitutes its foundation is lacking.”

From a Platonic point of view, this limitation imposed by Kant entails a risk, namely, deducing 'ideal logic' from an 'empirical logic', projecting, for example, the principle of causality even onto what, at the ideal level, is not the result of cause and effect, but a logical-metaphysical transformation determined by the quality of Time in act.

This was one of the first errors of the Aristotelians, which led them to imagine 'God' as the "Unmoved Mover" of reality, a thesis that generates serious aporias. We shall analyse this delicate point later.

By declaring Noumena 'unknowable', Kant thus changes the destiny of Philosophy. The domain of truth, in the modern sense of 'valid knowledge', is restricted to what can be traced back to possible experience. Whatever human beings claim to say about what is true must, in some way, begin from the Phenomenon.

And this, historically, will increasingly shift the axis of Philosophy towards Empiricism and towards the Human Sciences.

As we shall see more clearly later, unlike the intelligible entities imagined by Kant, the Forms of Pythagorean and Platonic Metaphysics do not produce a “new ontology”, that is, a fantastic world set against our own. They are not “things behind things”, but pure 'formal constraints'.

And insofar as they are constraints, they are primarily intuitable, and their correct deduction is the basis for reconstructing the structure of the Intelligible World. “To the Principle!”