Life, the philosophers say, should be spent in pursuit of happiness. We are bombarded with advice on what fulfilment looks like: on how to be, what not to do, improvement plans, mantras of wellbeing, being kind to oneself, and others. But such contentment, as Émilie du Châtelet points out, remains elusive. Nor is it a rational goal, however alluring. We can, at best, only see glimmers of such pleasures and recall them in retrospect. But if we can place these moments together, day by day, ac...