“We here propose to do just what Copernicus did in attempting to explain the celestial movements. When he found that he could make no progress by assuming that all the heavenly bodies revolved round the spectator, he reversed the process, and tried the experiment of assuming that the spectator revolved, while the stars remained at rest. We may make the same experiment with regard to the intuition of objects.”
– Immanuel Kant, Critique of Pure Reason, Preface to the Second Edition [B xv], Meiklejohn trans.
In any discussion of either Kant of the philosophy of the Enlightenment, this idea is one of the first we encounter. It is either noted simply as his “Copernican revolution”, or it is glossed in terms of scientistic hubris and a dangerous precedent for thought. I had regarded it more as the latter the first time I encountered this text, but upon reading it now, it has a decidedly different tone, one which causes me to silence the part of me that recognises and acknowledges metaphor when I encounter it. Instead, I think I am only just now getting what Kant is actually saying here. This language is considerably less figurative than I had at first thought (I may simply be slow, I make no claims to novelty here). It is not simply a rhetorical flourish; the extended metaphor of the successive governments of the queen of the sciences in the first preface illustrates that, at any rate, if Kant goes to the effort of devising a metaphor, he’ll get his thaler’s worth. Admittedly, he is not regarded as a master stylist, and if ever the joke “I am sorry for this being so long, but I hadn’t the time to make it any shorter” applied to a philosopher, well… Kant was it.
He is not attempting to point out that he is on the same level of awesomeness as Copernicus, nor is he attempting to arrogate some scientific kudos for critical philosophy. He is rather no more than noting that he is effecting a similar change of perspective. I assume that if one knows the name Copernicus, one understands that he was responsible for kicking off the modern shift in science away from an Aristotelian/Ptolemaic or geocentric conception of the universe (where the Earth stands at the centre, and everything else wheels off elsewhere with its epicycles and epicycles of epicycles &c.) to the modern, heliocentric model. With Copernicus and those who followed, we were no longer it. We were no longer the centre of the universe, except in our own feverish egotistical imaginings.
Another of Kant’s famous sentences, and one that he arranged that should be engraved on his gravestone is the following: “Two things fill the mind with ever-increasing wonder and awe, the more often and the more intensely the mind of thought is drawn to them: the starry heavens above me and the moral law within me.” The former is what concerns me more, even though the moral element is what gets more press (as much as transcendental critique gets attention these days). Nature and science were hugely important to Kant, and he was no mere dilettante. Accordingly, he had a proper understanding of what Copernicus had done. Where before astronomy had put humanity at the centre, the new heliocentric model did away with this, and in the process exposed our limitations. We did not know everything. Aristotle was not correct in all things (this was a serious epistemological threat to the church, thus the Inquisition requesting the pleasure of Galileo’s company).