For example, one of the great joys of literary life is eavesdropping on fine conversation. I do not mean ''Pass the salt'' or ''Watch the toast'' - the basic to-and-fro of domestic life. I mean instead the wit and wisdom of history's great talkers. Every Sunday evening, for example, the philosopher Alfred North Whitehead hosted conversations at his home. The discussions, which included his wife Evelyn and scholarly friends, are intelligent and very well informed, but they are also warm, generous and funny. Take his observation that ''deeply and truly religious persons are very fond of a joke'', and that he was suspicious of hyper-solemn clerics. Simultaneously a quip, a sincere profession of feeling, and a criticism of the wowserism that too often passes for piety. We expect scholars like Whitehead to have their moments of eye-twinkling mirth, but not authors like Emily Dickinson, usually taken as the archetypal hermit. The caricature is of a quiet, dour wallflower - yet she was anything but. One friend remembered Dickinson at the doorway, being asked about the big-boned housekeeper, mischievously nicknamed the ''Colossus''. ''She has rode,'' she quipped back, with a clever play on the ancient Greek statue.

Squeezed between professional and domestic labours, fine words can be rare, as can hours for good conversation. Biography collects these gems, scattered here and there over the centuries, and saves them in its textual treasury. Another pleasure is recognition: seeing one's own ideas or impressions in a stranger's life. Despite the distances that divide us - geography, era, class, gender - we suddenly read of some familiar kinship.

I was recently reading the memoirs of Leonard Woolf, the publisher, author, and husband to Virginia. At one point, he wrote of his wife's madness, arguing that there is no easy split between sanity and insanity. ''Everyone,'' he wrote in Beginning Again, ''is slightly and incipiently insane.'' In Woolf's careful phrasing, I recognised a thought I had long believed, but never articulated clearly. It was my own opinion, developed in another life, in the mind of a man born almost a century before me.

This is a double pleasure: not simply of intellectual clarity, but of solidarity. It is gratifying to look back over the decades or centuries, and see one's notions justified in a good life. It can compensate for the recognition often absent from professional or domestic life; the chronic loneliness of even the most gregarious life. It is also gratifying to flex one's imaginative muscles.

The philosopher David Hume once noted that the pleasure of curiosity was chiefly in exerting the intellect: the cognitive equivalent to enjoying burning lungs, straining calves during an uphill sprint. But this fulfilment also occurs with the imagination: putting oneself into another's life. The author Marcel Proust, for example, is a challenge for me to understand. Not his books or essays, but his character itself: his needy, hermetic, knowingly snobbish psyche is foreign to me. It is a genuine pleasure for me to try to grasp this persona. This is the fulfilment - equally important with living people - of giving another consciousness our full attention, and expanding ourselves as we do. So when some readers talk of a biography as ''delicious'' or ''mouth-watering'', it is not simply because of its titillating gossip or Lucullan feasts. It is because biographical writing is a genuine pleasure to read; to eavesdrop on great conversations and quips, to see oneself in another mind, and then to broaden this mind by sympathising with another.

There are other values, of course: moral and literary, to name the most obvious. We see the challenges and conquests of ethical life or art: Caesar's pride, Matisse's discipline. But biography is also a straightforward joy, which rewards patient, generous reading. Some of the most fun we can have between the covers - with a long-dead stranger.

Damon Young is a philosopher and the author of Distraction.

damonyoung.com.au