Nicholas Rescher argues that Kant’s radicalism is widely underestimated
To an extent that seems surprising, and that intimidates even his most dedicated followers, Immanuel Kant holds that the lawful order of the world’s phenomena inheres in the operation of our minds. He flatly maintains that “the order and regularity in the phenomena, which we entitle nature, we ourselves introduce”. He insists that nature’s laws are such that “we could never find them there, had not we ourselves, or rather had not the nature of our mind, originally put them there”. And as though rubbing salt in the wound of natural-law realists, he explicitly insists that “however exaggerated and obscure it may sound, to say that the understanding is itself the source of the laws of nature, such an assertion is nevertheless correct … Nature’s empirical laws are only the special determinations of the prime laws of understanding.” What we have here is a well-guarded secret, for Kantians all too seldom acknowledge this drastically idealistic feature of his approach to natural philosophy.
On Kant’s teaching, Nature’s particular laws implement and concretise the generic conceptions of lawfulness that characterise our thought through being mandated by the principles of reason. That the operation of the human mind is the basis and ground of the lawfulness of nature is a salient thesis of Kant’s critical philosophy. And he puts this idea to work across a wide terrain.
Now when Kant characterises man as the lawgiver of nature he subverts the Leibnizian philosophy by putting man in place of God. The lawfulness of Nature is grounded not – as Leibniz saw it – in the creative decrees of God, but in the formative make-up of human reason. Kant thought that just as Newton gave us the key to the laws of the material world, so Rousseau gave us the key to the laws of the human world. But this meant that the human world is also lawful. On this basis, a prioritising of rules, regulations, maxims pervades Kant’s philosophy, alike on the theoretical as on the practical side. For being law-conformable in thought and nature we are being true to our nature as a component of the wider nature of which it is a part. And the maxims of personal conduct in practical philosophy should form part of a spectrum of universal regularity that pervades the realism of nature and man alike. On this basis, Kant, a devoted student of the classics, resumed the Stoic theme that the realm of human agency should mirror that of nature as a manifestation of lawful regularity.
With Leibniz, the supreme duty of the human is to act so as to emulate God’s kingdom of grace; for Kant it is to emulate Newton’s kingdom of nature. Leibniz with his Principle of Perfection sought to render the operations of nature divine; Kant with his Categorical Imperative sought to make the operations of humanity natural – albeit in the manner of the lawful nature of Newtonian cosmology. And just here – in the concept of lawfulness – lies the fundamental unity of Kant’s theoretical and his practical philosophy.
But something even more far-reaching and grandiose is also at work here. What Kant is after throughout his philosophical work is to give us the philosophy of Leibniz without God – to put man in place of God and to have our human modus operandi substitute for that of the deity. Where Leibniz theologised nature through divine governance, Kant subordinated it to the mind of man. Space, time and causality – the very fabric of the universe – are for Kant no more than thought-forms of the human sensibility and understanding. And, analogously, for him the principles of morality are not divinely instituted but rather are inherent demands of our human rationality. Here too the mind of man is once again the pivot.
His early critics who charged Kant with being a follower of Berkeley could not have been more wrong. For with Berkeley – just as with Descartes and Leibniz – God did all of the heavy lifting in philosophical explanation. But with Kant the inherent workings of the human intellect accomplished the needed work.
To Kant’s mind, all of the tasks that Western philosophical thought has traditionally assigned to the deity as institutor of a rational world-order do indeed need to be accomplished, but humanity– we mere mortals – are up to the task. What we have here is a philosophy not so much of enlightenment as of enormous hubris. For Kant qualifies – and perhaps saw himself – as the philosophical Prometheus who brought the power of God down into the domain of humanity.
Nicholas Rescher is University Professor of Philosophy at the University of Pittsburgh and the author of over 100 books, including Philosophical Dialectics: An Essay on Metaphilosophy (SUNY)