Spock, in Star Trek II: The Wrath of Khan (1982), saved the crew of the Enterprise at the cost of his own life. Dying of radiation poisoning, he utters: ‘It is logical. The needs of the many outweigh … the one.’ On the basis of utilitarianism he sacrifices himself. Why? (Paramount Pictures)

Why does anyone do anything for others? Arguably, they don’t, for there isn’t such a thing as a selfless act. Members of ego-less species seem capable of selflessness, though. Take bees and ants—they search for and share food for the good of the colony. Perhaps, then, some of our behaviours are guided by things bigger than ourselves too. After all, people spend money they don’t have on those they love; despite wanting to live, they take bullets and jump on grenades for fellow soldiers; they deliberately kill themselves for the sake of an ideology. These people negate or at least reduce the evaluation of their own interests in sight of others’.

Conversely, perhaps these are their best interests. This, for instance, can be analysed in terms of Darwinian altruism: viz, the individual acts for the good of their genes, expressed through something personal like empathy. Alternatively, we may look to Freudianism: the individual acts for the maximisation of their pleasure; helping makes them feel good. Sam Harris once said:

'A wisely selfish person more and more begins to recognise that he or she is committed to the happiness of other people … their happiness redounds to their own happiness.'

Many disagree. They claim morality is constituted in us through our ability to reason or through our connection to the divine (inter alia).

So do we find examples of people acting out of pure kindness? Friedrich Nietzsche was sceptical. In fact, he kind of deplored the whole idea. In Beyond Good and Evil he writes:

‘[T]he sentiment of surrender, of sacrifice for one’s neighbour, and all self-renunciation-morality, must be mercilessly called to account, and brought to judgement; just as the aesthetics of “disinterested contemplation”, under which the emasculation of art nowadays seeks insidiously enough to create itself a good conscience. There is far too much witchery and sugar in the sentiments of “for others” and “Not for myself”. [Ask]: “Are they not perhaps—deceptions—that they please him who has them, and him who enjoys their fruit" […] Let us therefore be cautious!’

Still, most of us haven’t given up on morality just yet. Why not?