“Happiness is always a by-product. It is probably a matter of temperament, and for anything I know it may be glandular. But it is not something that can be demanded from life, and if you are not happy you had better stop worrying about it and see what treasures you can pluck from your own brand of unhappiness.”
— Robertson Davies
Brad DeLong's head may explode, but you know what Davies means. An unhappy life is not a life without value. Indeed, there may be treasures in unhappiness. There is evidence that happier people are more self-deceiving, for instance. So it may be that unhappiness enables self-knowledge, or outward knowledge unclouded by the mists of optimism. Of course, one is not made happier by dwelling on unhappiness, so refusing to dwell on it may mitigate it. But refusing to dwell on it also allows one to reorient to other values–knowledge, virtue, spiritual communion–one may, unhappily, achieve. This reorientation may, in the end, bring some measure of happiness. Yet even if it doesn't, life will be better for it.