The title of this small book might suggest bland reading, but its authors  a psychoanalyst and a historian  rummage around the darker corners of the human heart, trying to understand why we find benevolence so disturbing. Despite its brevity, the book presents a nuanced anatomy of kindness, drawing on thinkers from Seneca to Freud to show that it contains everything we are afraid of in ourselves: desire, jealousy, hatred and self-interest. Phillips and Taylor also argue that while kindness has long been central to our concept of good living, it has recently been marginalised and undermined by the rise of individualism. But as the book's hero, Jean-Jacques Rousseau, passionately asserts, caring for others doesn't simply bring us happiness  it is essential to our survival.

Late in this book, we are told of the lengths some companies, renowned for their rapacious, unfeeling capitalist tendencies, go to in order to make it seem as though their employees are full of "warmth" and "empathy". "The ironies", we are told drily, "are not subtle ones." However, as we learn here, kindness itself involves not so much subtle ironies as wildly counter-intuitive ones. For this co-authored book (more of a long pamphlet, really) is composed of two very different parts: one is a historical overview, presumably written largely by historian Barbara Taylor, and the other is by Adam Phillips, the acclaimed psychoanalyst.

Taylor begins with a largely uncontentious reading of attitudes to kindness (or, in Christian terminology, caritas), taking us from the Stoics to the modern age, her longest digression being on Rousseau's Emile, for whom kindness is an extension of his self-love. I am surprised, incidentally, that Taylor does not mention Bernard Mandeville's hugely influential Fable of the Bees, which proposes that it is our tendency to vice, pleasure and selfishness which actually keeps society going. And you don't have to be a conservative, as Taylor claims, to denounce Rousseau as "a mealy-mouthed hypocrite".

But anyway. It is as Phillips gets into his stride that you can hear the commonsense Englishman begin to harrumph. You can almost sense the bellows of outrage when he says, apropos of love, that "the person who might seem most essential to us becomes the person who is most replaceable"; or, quoting Freud: "it must nevertheless be said that anyone who is to be really happy and free in love must have surmounted his respect for women and must have come to terms with the idea of incest with his mother or sister."

That last is just the kind of thing that makes the believer in "common sense" reject Freud, and by extension the psychoanalytic project itself (actually, I have more problems with the book's initial assertion, that we are suspicious of kindness these days, or that "kindness has always been contentious"). But psychoanalysis is, as Phillips puts it, "an account of how and why modern people are so frightened of each other", and if in trying to uncover our hidden motivations he disturbs a lot of muddy soil then that could well be an indication that he, and his mentors, are on the right track.

A faith in "common sense" is not going to be one that can easily accommodate the paradoxes of our emotional lives; and Phillips certainly does a good job of persuading the reader about Freud's remark about love and incest. So this book isn't just about kindness; it's also about love, and fellow-feeling and humanity. It is a decent attempt to be both emotionally and politically useful (kindness is a good meeting-point for the two, which is why this is actually quite a clever collaboration between psychoanalyst and historian), and so is useful whether our concern is the ideal society or the ideal person. Those of us who puzzle over the eternal mystery of love would do well to read it. The vast bulk, if not all, of psychoanalytical literature attempts to deal with this somewhat intractable problem, but Phillips's prose is more elegant than most.

On Kindness deals, en passant, with many varieties of love, from whether, say, you can have a particular "type" you tend to fall in love with, to how children get on with their mothers, or rather vice-versa (upon which, "nothing less than the future of western civilisation might depend").

The book ends, or almost ends, with a ringing denunciation of free-market economics, which might slightly be slamming the stable door after the horse has long since vanished, but at least it is music to our ears, and does set up the final conclusion: that kindness is not something to be taught, but to be reawakened, and to be performed instinctively, intuitively, for the good of society as a whole. As the Bible says, when performing acts of charity, the left hand should not know what the right hand is doing.

Adam Phillips is a psychoanalyst, Barbara Taylor a historian, specifically a historian of ideas. Between them they explore the concept of "kindness", its status among human attributes and the value that has been ascribed to it over the years. "Kindness" is a rough equivalent of the Christian non-erotic love, or charity, though it was embraced as a virtue and a source of pleasure by Cicero, for one, and by the Stoic emperor Marcus Aurelius, before it was extolled famously by St Paul in his Epistle to the Corinthians. Charity, except in the limited context of organisations such as Oxfam or Mind, is not an attribute much favoured today, being thought inimical to equality and the recognition of rights. Part of the purpose of this short book is to reinstate it as something necessary both to our personal happiness and our communal well-being. This seems to me a totally admirable aim.

Kindness to others arises out of sympathy. As the authors note, there is much evidence that other animals besides human beings (or "men" as they properly designate them) can enter into the sufferings and fears of others of their kind. But it is human animals alone who, because of their imaginative powers, can enter into the feelings of other people far removed from them, whom they cannot see or touch, but whose plight as fellow-humans they can share

In the Gospel of St Luke, a lawyer is told by Jesus that to live well he must love his neighbour as himself and, when he further asks who is to count as his neighbour, Jesus answers with the story of the good Samaritan, for many the very essence of Christianity. Kindness here arose spontaneously, not in obedience to any rule, in fact in defiance of convention. But as Christianity became increasingly ecclesiastical and hierarchical, with the consequent corruption of the priesthood, the good Samaritan was forgotten.

The new Protestantism declared man to be fundamentally sinful, such good actions as he could do dependent on the grace of God; and so the possibility of natural kindness disappeared. Separately, in the 17th century, Thomas Hobbes, an atheist and materialist, presented a picture of human life as a perpetual struggle for power, a war of all against all, which could be civilised only by the absolute political rule of a sovereign.

It was Hume, that most humane and far-sighted philosopher, who, in his A Treatise on Human Nature (1740), introduced sympathy as the necessary foundation of morality. He insisted, in his later work, that sympathy for others was experienced by everybody, part of the nature of man. But the most powerful exponent of man's natural goodness was Rousseau, whose influence on Romanticism throughout Europe it is impossible to exaggerate.

The most fascinating part of this story is how the great charitable philanthropists of the 19th century, the industrial giants of their day, the founders of schools, hospitals and universities, came to be denigrated, charity itself becoming suspect, a thinly disguised form of imperialism, an assertion of power or an assuaging of guilt.

Having given us an entirely readable and absorbing short history of kindness, or caritas, Phillips and Taylor follow up with two chapters on the psychoanalytical take on the concept. This is a bit of a shock to the reader, the gear-change needed being quite violent. It is not the common difficulty of relating particular case histories to generalities and trends, but, rather, that the apparatus of psychoanalysis demands a suspension of scepticism that most of us do not feel when reading history, however compressed. There, we get caught up in the story, can recognise the trends and say: "Just So." But because the emotions and impulses of the individuals studied by psychoanalysts - their aggressions, their desires, their hatreds and their loves - are for the most part unrecognised even by them (except perhaps after lengthy treatment), one has the constant desire to stop and say: "I don't get it." Things become a bit easier when we leave Freud behind and move on to psychoanalysts such as Bowlby and Winnicott. The idea that enduring, reciprocal love or tolerance between parents and children cannot arise until both parties know the worst of each other and learn to accept each other as they are seems profoundly true. This is certainly kindness.

The joins between the two parts of the book are mended, in part, in the final chapter. Psychoanalysis has, according to the authors, revealed what history has more openly demonstrated and philosophy has, sometimes, argued - that "human beings... are ambivalent creatures. Kindness comes naturally to us, but so too do cruelty and aggression". Compassion is a virtue, and what Hume would call a natural virtue, but we may easily be tempted to suppress our compassion, which is always risky and may sometimes misfire. Yet one thing is beautifully demonstrated in this last chapter. "Caring", as we now know it (including "care-packages" and pre-ordered smiles), is no substitute for kindness. The critique of the Blairite descent from the ideals of the NHS, a service that started in kindness, is funny but sad.

I hope that the brevity of this book will not tell against it. A concentrated essay on a limited but deeply important subject is to be highly valued.

 Mary Warnock's most recent book, with Elisabeth Macdonald, is Easeful Death: Is There a Case for Assisted Dying? (OUP).