While discussing space, Hegel states that the Kantian theory of space – if the subjective idealism of this theory is ignored – is a good explanation of space. And indeed, the way Hegel describes space here is very similar to what Kant in his Critique of Pure Reason says about space.
Both philosophers insist on the fact that space must not be taken as a reality in itself, namely as an empty box, albeit devoid of any limits, and which, therefore, as Kant puts it, would be a sort of self-contradicting thing, an existing non-existence, an Unding.
But then, you might ask, what is the difference between these two interpretations? Why can Hegel consider that what for Kant had been only a humanly necessary condition for the intelligibility of space and nature is now for him an objective condition of nature.
First of all, we must abandon the idea that nature and space are something independent of human cognition. According to Hegel, it is not, as Kant thought, that on the one side lies objective nature and on the other hand man with his spatial spectacles.
In fact, as in Kant, in Hegel there is a continuity between spatial nature and spatial consciousness. But unlike in Kant, for Hegel, this continuity is not based on the idea of phenomenality but on the idea of intelligibility, of the possibility to think nature and space. If one takes space as an intuition, then one puts this entity on the subjective side. Space then becomes the necessary spectacles through which we humans perceive nature.
But this is only an interpretation of space, and this interpretation is based on metaphysical assumptions. Changing the metaphysical assumptions, one can get a different interpretation of space by retaining the description of the same fact, so to speak.
Space is not there objectively in Hegel either. The difference is that, instead of having a nature that is dependent on human categories and conditions of pure intuition, in Hegel, we have an objective nature – in which human being is a necessary part – that grows toward human consciousness and carries within itself all the conditions of future human intelligibility.
Thus, space is pure externality or self-externality, says Hegel. This proposition is true both in Kant and in Hegel. In Kant, this pure self-externality makes us capable of intuiting things separately as being different entities.
In Hegel, on the other hand, this self-externality is a condition of the very being of things. Kant considers that the conditions of our knowledge are conditions of being itself, whereas Hegel, inversely, considers that the conditions of being are conditions of human knowledge.
This is a confusion, a logical error, a Kantian might say: you may not set the conditions of nature, or being in general, as conditions of human knowledge because, while you set the conditions of nature, you are already within that knowledge and posit those conditions according to its requirements. Thus, you commit a circulum vitiosum, a vicious circle, attempting to prove something as true that you have already assumed to be true.
This seems so obvious; how could Hegel not have grasped this error? Because, in fact, there is no error. While Kant states that the conditions of being must be set according to the conditions of knowledge, he already asserts a metaphysical hypothesis as truth, namely the insurmountable gap between the objective being and human knowledge.
But this is only a metaphysical hypothesis that cannot be proved at all due to its metaphysical character. Thus, when I say that everything must conform to my knowledge, this requirement introduces, through the backdoor, so to speak, the idea of the ontological difference without being aware of it and especially without any possibility of proving it.
Indeed, Kant attempted to prove his metaphysical perspective by explaining the a priori character of scientific knowledge, which would be impossible if that a priori character were not a result of the knowledge conditions themselves.
He assumed that knowledge could have only two origins: the external affection of the things in themselves (with regard to the material character of knowledge) and the a priori structure of the human mind (concerning the formal character of knowledge).
Scientific predictions would be based on the a priori structure of the human mind: it is because we cannot perceive nature otherwise than according to our mind’s structures that we can establish scientific predictions about natural processes – thus says Kant.
In this context, we must highlight that for Kant, a priori knowledge cannot have an external source. For him, knowledge is either empirical – and then it is completely based on the past, being simply a generalization of our past experience – or, if scientific, its a priori character cannot originate in the outside world. And this latter proposition expresses exactly his metaphysical skepticism.
But there is no reason why along with the sensations we get from outside, we should not also receive their a priori order. The Kantian metaphysical premise is that sensations, as a matter of knowledge, have a chaotic character that must be ordered and in-formed through the human mind’s structuring faculties.
Now, if we think of space as a condition of intelligibility of nature that is not posited by human thought but pertains to nature itself, and we also think of the human mind as having ultimate unchangeable structures, we may consider these structures as expressions within our intellect of objective intelligibility.
Obviously, they cannot be products of reflection because now, the order of sensations, like the order of things and as following the latter, is a direct product of God’s creation, and we cannot follow that creation upstream to God. By positing the sensations as ordered within the general framework of intelligibility, we relate directly both the world itself and human thought to God as their common Creator. It is God’s decision to make them correspond and not the result of the synthetic activity of the human faculties.
Interestingly enough, Kant based the whole synthetic activity of the human mind on a ‘blind faculty’ – the productive imagination – which, as Hegel rightly points out in his Philosophical Studies, was nothing else than another name for God.