In recent weeks, I've seen a production of Puccini's ''Turandot''; stood in front of one of Monet's paintings of Rouen Cathedral; and heard a recording of Bach's Four Orchestral Suites.
What interests me is that nobody once asked, ''Why are you doing that?''
If they had, I might have replied as the mountain climber did when asked why he scaled the peak: ''Because it was there.'' To produce ''Turandot'' requires massive effort: When it's there, you go see it. But there's more to it. The Monet hangs permanently in Boston's Museum of Fine Arts; the Bach has been on my shelf for years. Why reacquaint oneself with them? Because, as grand works of art, they are worth experiencing again and again for their insight into humanity and their masterly presentation of aesthetic balance.
The same holds true, or ought to, for great literature. Yet something in our age seems to militate against rereading. The same people who listen to Bach lament the lack of good books. They need no excuse to sit before a Cezanne; but seeing you reading Dickens, they ask, ''Why are you reading that?''
Well, I sympathize. With nearly 1,000 new books published in the US each week, the pressure to stay informed weighs heavily. But there is a difference between information and wisdom. Reading informs; but rereading is the route to thoughtfulness. ''No book is worth anything which is not worth much,'' wrote John Ruskin, ''nor is it serviceable, until it has been read, and reread, and loved, and loved again.''
All these things were on my mind recently when, departing for a holiday weekend, I left the new books behind and took instead my much-rumpled copy of Joseph Conrad's ''Heart of Darkness,'' first published in 1899. Plunging again into that astonishing tale - ostensibly about a journey up the Congo River during the days of the Belgian empire, but in fact a study of the glory and the horror of colonization, of the nature and essence of evil, and of the way language works to hide and reveal meaning - I was struck anew by the value of rereading.
For the re-reader no longer has to worry about whether the book is really worthwhile. As with Bach and Monet, one knows that the work will not disappoint. So one doesn't reread to criticize. One rereads to learn. Nor is plot paramount. Knowing what will happen, re-readers find subtle nuances of language drawing new meaning from already-known conclusions. The result: an attention to detail that focuses less on where the book is headed than on how it gets there. The re-reader can indulge in that greatest of luxuries: the contemplative pause.
But the most valuable reward comes in reapplying old lessons to current needs. When I last read ''Heart of Darkness'' six years ago, the jungles of Central America were not in the news, nor had the Soviets invaded Afghanistan. Conrad, in his way, addressed himself to these things - and to the motives leading some nations to attempt to ''civilize'' others.
Which is not to say that books on the USSR and on Central America are not worthwhile. But so is a reacquaintance with books already read. It lifts us from the lust for the merely new - surely one of the subtlest temptations of today - to recognition of the truly profound. For something in our age also seems to militate against profundity - asking, right at the point of deepest contemplation, ''Why are you doing that?'' The answer isn't just ''Because it's there.'' The answer is that what matters in a troubled world is not more knowledge but deeper thought. To reread Conrad is to think more deeply about that world.