The Abolition of Man

by C.S. Lewis

But why ought we to obey Instinct? Is there another instinct of a higher order directing us to do so, and a third of a still higher order directing us to obey it?—an infinite regress of instincts? This is presumably impossible, but nothing else will serve. From the statement about psychological fact ‘I have an impulse to do so and so’ we cannot by any ingenuity derive the practical principle ‘I ought to obey this impulse’. Even if it were true that men had a spontaneous, unreflective impulse to sacrifice their own lives for the preservation of their fellows, it remains a quite separate question whether this is an impulse they should control or one they should indulge. For even the Innovator admits that many impulses (those which conflict with the preservation of the species) have to be controlled. And this admission surely introduces us to a yet more fundamental difficulty.