The difficulty with science, for most of us, is finding the way in. One of the gentlest approaches is to see how scientists themselves found their themes and warmed to them: Darwin is ideal, being both worldchangingly significant and immensely sympathetic. Janet Browne's Charles Darwin: The Power of Place (Cape, £25) depicts him in the squirish solidity of Down House, in Kent, and the warmth of his family.

Behind the patriarch's beard was a loving father and husband - a heartfelt "God bless youî jotted upon a letter his wife wrote him, urging him to take comfort in the faith that sustained her; happy nights with his son in the autumn of his life, digging up worms in the garden for experiments. He approached closer to a modern ideal of manhood than a Victorian stereotype.

His courage was also of an unusual kind: determined, but anxious and accommodating. Browne's book is an outstanding achievement that will set the standard for Darwin biographies, but its one shortcoming is that it does not seize upon the way that Darwin drew back, in the face of criticism, from the idea upon which his greatness rests. The point of Darwin is not that species evolve, but that this happens by natural selection.

It's a terribly simple idea, with fiendishly complicated implications. One of its biggest puzzles is why sex exists; but whatever the reason, the ways creatures have it are as eye-popping and motley as anything in nature.

If you want to get into science after the watershed, try Dr Tatiana's Sex Advice to All Creation: The Definitive Guide to the Evolutionary Biology of Sex, by Olivia Judson (Chatto, £16.99). Despite the racy tone of the agony aunt's tips for sundry species, it's serious underneath, highly effective in making its points stick, and it honours the spirit of natural history with its exuberant appreciation of the diversity of life. Top take-home message: "The battle of the sexes erupts because, in most species, girls are wanton."

But it's our own species whose instincts get us hot under the collar, though. This year's big event in the nature-nurture debate was Steven Pinker's The Blank Slate: The Modern Denial of Human Nature (Allen Lane, £25). Much of his case is hard to deny, but the book's insistent sectarianism makes it hard to love. Still, at least words are the only weapons in this controversy.

The tale of The Lunar Men: The Friends Who Shaped the Future, by Jenny Uglow (Faber, £25), turned sorry after the laboratory and home of one of them, Joseph Priestley, were destroyed by a mob in the name of "Church and King".

Here the reader sees science with its sleeves rolled up, amid the head of steam generated by a group of 18th century movers and shakers, building factories, experimenting with gases, thinking the unthinkable, and making money.

Practical men above all, the men of the Lunar Society (named because it met at full moon) were concerned with the basics: clay for pottery, oxygen for breathing.

Philip Ball takes a similar view. His tour of the elements, The Ingredients (Oxford University Press, £13.99) concentrates on the staples, like gold; and water, for he considers ancient ideas about the elements as well as modern ones. Though it's a little disappointing that there's nothing to fill the magical promise of names like yttrium and tantalum, Ball's choices are sound, his style is attractive, and his touch is light.

The elements aren't really the basics, though. Science is a study of relationships, which it seeks where possible to express in equations - and that's just what scares most of us off. It Must Be Beautiful: Great Equations of Modern Science (Granta, £20), a collection of essays edited by Graham Farmelo, is a valuable exercise in bridging the gap between those who think in words and those who think in maths.

The essays make sense of the symbols, and of the historical moments in which they are embedded, from the building of the Bomb to the search for life around other suns. Getting to the heart of science may be easier than you think.

Marek Kohn's As We Know It: Coming to Terms with an Evolved Mind is published by Granta.