René Descartes’ method gave us a way to find truth by making a clear distinction between subjectivity and objectivity.
Subjectivity, the particular way of looking at the world that is unique to each of us, is to be roundly distrusted because of the way it distorts understanding: introducing errors of judgement, errors of perspective, and the errors that come from being confused by our emotions, bodily sensations, commitments and desires.
Objectivity, the way of looking at the world that comes from dispassionately observing and measuring the properties of things, can be trusted – as long as careful observations are made and conclusions formed by the step-by-step application of tried and tested methods of reason and logic.
By restricting what we take to be true to that which can be found in the objective and logical realm, Descartes gave us a powerful way of establishing truths that had previously eluded us. No longer did we have to believe that flames go upwards because it is of the essential nature of fire to rise above other kinds of matter, and no longer did we have to believe that the sun and stars went around the earth because it is the essential nature of human beings to be the centre of things. We could observe, and test, and reason and conclude, establishing cause and effect relationships free from superstition and free from prejudice.
It was a world-changing shift of perspective that moved reason to the centre after centuries during which it had been in the margins. At the same time, it established mathematics and physics as the central sciences. Mathematics took up a particular specialness because of its power to explain and predict without recourse to any subjectivity or, indeed, any need to rely even upon the physical, objective world in order to do its work.
It’s hard for those of us who have grown up in the world ushered in by Descartes and his enlightenment contemporaries to see what a radical change this was, so schooled have we been in its assumptions and its way of looking at things. But we can see it in the way we go about science and proof, in the way we look for particular kinds of facts or measurements before we’ll take something as true, in the way we make ‘objective’ more important or valid than ‘subjective’, and in the explosion of science and technology in our era. There’s no doubt that our world would be radically different, and in so many ways vastly impoverished, without our having taken up reason as the central project of the last few hundred years.
But I think it’s worth asking questions about where we have taken Descartes’ project too far. We routinely rely on it to produce truth in fields where its methods and its insistence on discarding the subjective lead us to look in a narrow way and can direct us into all kinds of confusion. How we educate our children and ourselves, and about what, working together in organisations, pursuing what’s meaningful rather than what’s simply useful, being in relationship, loving others, community, art – each of these are among the fields where the subjective, where our experience of things, is central, and no recourse to a subjectivity-free objectivity can hope to show us much. And reason, while vital in establishing truth (I would not want to do without it!) cannot help us alone with two other important human projects – beauty and goodness – both of which are vital if we are to have flourishing and ethical institutions, politics, education and organisations.