This Day in Philosophy — 8 August: Arnauld dies, Hutcheson is born

8 August 1694 is one of those rare dates on which the history of philosophy records two events at once: one thinker dies as another is born.

Antoine Arnauld (1612 – 8 August 1694)#

The French theologian and philosopher Arnauld was the most formidable pen of the Jansenist movement that gathered around the abbey of Port-Royal, outside Paris. In the history of philosophy, though, his name is remembered for two separate contributions.

The Port-Royal Logic. La Logique ou l'art de penser (1662), written with Pierre Nicole, was for a hundred and fifty years the standard textbook of logic in Europe. The novelty of the book lay in taking logic out of barren exercises in the syllogism and presenting it as the art of thinking well. It is also the book that spread a distinction still in use today: the distinction between the extension and the intension of a concept.

Objections to Descartes. Arnauld wrote the fourth of the sets of objections put to Descartes's Meditations. The criticism he made there is known today as the Cartesian circle: Descartes grounds the truth of our clear and distinct perceptions in the existence of God; but if he proves the existence of God by clear and distinct perceptions in turn, has the proof not swallowed its own tail?

Arnauld also carried on long correspondences with Leibniz and with Malebranche. Seventeenth-century philosophy took much of its shape in those letters.

Francis Hutcheson (8 August 1694 – 1746)#

The Scottish philosopher Francis Hutcheson, born on the same day, is counted among the founding figures of the Scottish Enlightenment. He held the chair of moral philosophy at the University of Glasgow; Adam Smith was his pupil.

Hutcheson's central concept is the moral sense. Our capacity to tell good from bad, on his account, does not derive from a calculation of interest or from abstract reasoning. Just as the eye sees colour, there is in us a sense that approves virtue directly. When we find an action good, we do not first work out where our interest lies and then approve; the approval comes of itself.

The view was an open rejection of Thomas Hobbes's picture of human nature. But one sentence of Hutcheson's has lived a great deal longer: "That action is best which procures the greatest happiness for the greatest numbers." The classic formula of utilitarianism was uttered here half a century before Jeremy Bentham.