The Enlightenment Vision of Science and Religion #22: Kant and His “Copernican Revolution” of Philosophy

The Enlightenment Vision of Science and Religion #22: Kant and His “Copernican Revolution” of Philosophy

God has conferred upon and added to man a distinctive power — the faculty of intellectual investigation into the secrets of creation, the acquisition of higher knowledge — the greatest virtue of which is scientific enlightenment.


Apr 8, 2013. One of the last – and probably the greatest philosopher – of the important enlightenment thinkers was Immanuel Kant (for the Wikipedia entry, see Kant). To understand his importance, it is worth quoting the Stanford Encyclopedia of Philosophy:

Immanuel Kant (1724–1804) is the central figure in modern philosophy. He synthesized early modern rationalism and empiricism, set the terms for much of nineteenth and twentieth century philosophy, and continues to exercise a significant influence today in metaphysics, epistemology, ethics, political philosophy, aesthetics, and other fields.

What did Kant have to say about the all-consuming themes of the enlightenment – philosophy, religion, atheism, science, reason, rationalism, and empiricism? Again, to quote the Stanford Encyclopedia:

He argues that the human understanding is the source of the general laws of nature that structure all our experience; and that human reason gives itself the moral law, which is our basis for belief in God, freedom, and immortality.

In short, all understanding – be it of God, of science, of religion, of anything – stems from the structures of understanding built into our mind – “the mind actively structures how we see the world“. So reason and scientific investigation are of central and absolute importance, but, what it reveals – and the limitations of what it can reveal – are determined by how the mind works.

What follows is Kant’s “grand synthesis:

Therefore, scientific knowledge, morality, and religious belief are mutually consistent and secure because they all rest on the same foundation of human autonomy, which is also the final end of nature …

But, like a beautiful California beach covered with brilliant and alluring white sand opening on a crystalline aqua ocean, there are problems in the depths.

On California beaches, it is the deadly undertow and the sneaker waves that can drag the unwary to their death (and, of course, the occasional shark). For the inheritors of Kant’s philosophy – Hegel, Marx, Freud and others – it is that the hidden and unknowable structures of the mind take on a life of their own – powerful and corrosive nationalisms, dialectical materialisms, or hidden and base roots of behavior – and that catastrophic consequences in the moral, political, and financial worlds follow.

Kant’s Copernican Revolution

Kant was born in Konigsburg, in the northern part of Prussia bordering modern Lithuania. He never strayed.

At first a reasonably conservative and popular university lecturer, he taught a mix of the rationalism of Leibniz and Wolff – the great German thinkers of the day – and the empiricisms of Newton and the British philosophers, including the famously skeptical David Hume.

But how could these seeming incompatible sources of knowledge – rationalism and empiricism – be reconciled to each other? A big part of the problem was that of the intellect. How could the intellect – and reason – obtain to knowledge? If, as the Enlightenment loudly and often proclaimed – reason and thought was the key to understanding everything, even religion – then how can we understand reason’s ability to work in such powerful and all-embracing ways?

It was Hume’s challenge to the usual understanding of the workings of cause and effect that awoke Kant from his “dogmatic slumber”,  Describing this awakening, he later wrote:

I freely admit that it was the remembrance of David Hume which, many years ago, first interrupted my dogmatic slumber and gave my investigations in the field of speculative philosophy a completely different direction.

Fr. Seamus Mulholland, writing on Kant on the Pathways School of Philosophy website, summarizes Kant’s approach to reconciliation:

As he saw it, rationalism operates in the sphere of innate ideas, with their analytical and therefore aprioristic ideas; this necessity, however, is not based on experience and consequently does not apply to reality itself. On the other hand empiricism starts completely from experience and thus (it seems) from reality, but it arrives only at a posteriori and therefore synthetic statements that lack necessity.

Kant sought to unite the concept and experience; he sought a necessity that extends to the order of objective reality and an order of objective reality that in itself contains necessity.

The Stanford Encyclopedia puts it in slightly different terms. Referring to Kant’s magisterial – and nearly impenetrable – Critique of Pure Reason – it explains his thinking:

However, Kant’s revolutionary position in the Critique is that we can have a priori knowledge about the general structure of the sensible world because it is not entirely independent of the human mind. The sensible world, or the world of appearances, is constructed by the human mind from a combination of sensory matter that we receive passively and a priori forms that are supplied by our cognitive faculties. We can have a priori knowledge only about aspects of the sensible world that reflect the a priori forms supplied by our cognitive faculties.

In Kant’s words, “we can cognize of things a priori only what we ourselves have put into them”. So according to the Critique, a priori knowledge is possible only if and to the extent that the sensible world itself depends on the way the human mind structures its experience.

Kant described his new thinking as his “Copernican Revolution”. When Copernicus couldn’t make sense of the idea of a universe centered on the earth, he flipped things around to see if it made better sense when the sun was at the center of the universe:

Up to now it has been assumed that all our cognition must conform to the objects; but all attempts to find out something about them a priori through concepts that would extend our cognition have, on this presupposition, come to nothing. Hence let us once try whether we do not get farther with the problems of metaphysics by assuming that the objects must conform to our cognition, which would agree better with the requested possibility of an a priori cognition of them, which is to establish something about objects before they are given to us.

This would be just like the first thoughts of Copernicus, who, when he did not make good progress in the explanation of the celestial motions if he assumed that the entire celestial host revolves around the observer, tried to see if he might not have greater success if he made the observer revolve and left the stars at rest.

The Crisis of the Enlightenment

Kant’s thinking came at the end of the Enlightenment when the attacks on morality and religion – especially from British empiricists and French deists and atheists – was reaching a crescendo. The French revolution was about to happen – and its celebration of reason gone awry was the harbinger of the first of the great world wars. Soon militarism, Napoleonic frenzy, and unrestrained nationalism was to throw Europe and much of the world into chaos. And romanticism – the celebration of passion and elevated states of feeling – was at the door and ready to take over.

The Enlightenment was the celebration of reason – and of science in general and Newtonian science in particular. It opened up vast new vistas of progress. But, how could order and coherence be maintained if everyone were to think willy-nilly just for themselves and not for the general good?

According to the enlightenment, reason was the judge. Kant proclaimed:

Our age is the age of criticism, to which everything must submit. Religion through its holiness and legislation through its majesty commonly seek to exempt themselves from it. But in this way they excite a just suspicion against themselves, and cannot lay claim to that unfeigned respect that reason grants only to that which has been able to withstand its free and public examination.

But everybody was supposed to think for themselves. And the path forward was unclear. At the heart of the crisis of the enlightenment was the “sovereignty of reason.” Again, the Stanford Encyclopedia:

The problem is that to some it seemed unclear whether progress would in fact ensue if reason enjoyed full sovereignty over traditional authorities; or whether unaided reasoning would instead lead straight to materialism, fatalism, atheism, skepticism, or even libertinism and authoritarianism.

The Enlightenment commitment to the sovereignty of reason was tied to the expectation that it would not lead to any of these consequences but instead would support certain key beliefs that tradition had always sanctioned. Crucially, these included belief in God, the soul, freedom, and the compatibility of science with morality and religion. Although a few intellectuals rejected some or all of these beliefs, the general spirit of the Enlightenment was not so radical. The Enlightenment was about replacing traditional authorities with the authority of individual human reason, but it was not about overturning traditional moral and religious beliefs.

But if science – especially Newtonian mechanistic science and its clockwork mechanisms that deny the existence of the soul and freedom of choice – is the essence of reason and rationality, what does the Enlightenment really have to offer? And what if “modern science, the pride of the Enlightenment, the source of its optimism about the powers of human reason” was the cause of undermining “traditional moral and religious beliefs that free rational thought was expected to support?”

Kant claimed to have solved the problem. He claims to have proven that “a critique of reason by reason itself, unaided and unrestrained by traditional authorities, establishes a secure and consistent basis for both Newtonian science and traditional morality and religion.”

Next Time

But did Kant really solve the problem? Does free rational inquiry – of and by itself – support morality, the need for order, and other human interest? Does reason deserve “the sovereignty attributed to it by the Enlightenment?” We address these and other question in fuller detail in the next blog when we look at Kant’s defense of religion.


This is the 22nd in a series of blogs on the Enlightenment Vision of Science and Religion. The author, Stephen Friberg, is a Bahá’í living in Mountain View, California. A research physicist by training, he wrote Religion and Evolution Reconciled: ‘Abdu’l-Bahá’s Comments on Evolution with Courosh Mehanian. He worked at NTT in Japan before joining the semiconductor industry in Silicon Valley.

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