The method used by the virus to cross from one species to another, the method of random mutation — try everything, see what works — cannot be said to be arrived at by rational planning. The individual virus does not have a brain and therefore a fortiori does not have a mind. But if we want to be resolutely materialist, we can say that the thinking (the rational thinking) employed by human beings as they try to find ways of annihilating the virus or denying it a home in the human population is also a process of trying out biochemical, neurological options, under the command of some master neurological programme called the reasoning process, and seeing which one works. To a radical materialist, the broad picture is thus of two forms of life each thinking about the other in its own way — human beings thinking about viral threats in the human way and viruses thinking about prospective hosts in a viral way. The protagonists are involved in a strategic game, a game resembling chess in the sense that the one side attacks, creating pressure aimed at a breakthrough, while the other defends and searches for weak points at which to counterattack.

What is disturbing about the metaphor of relations between human beings and viruses as a chess game is that the virus always plays with the white pieces and we human beings with the black. The virus makes its move, and we react.

Two parties who embark on a game of chess implicitly agree to play by the rules. But in the game we play against the viruses there is no such founding convention. It is not inconceivable that one day a virus will make the equivalent of a conceptual leap and, instead of playing the game, will begin to play the game of game-playing, that is to say, will begin to reform the rules to suit its own desire. For instance, it may choose to discard the rule that a player shall make only one move at a time. How might this look in practice? Instead of striving as in the past to evolve a single strain capable of overwhelming the host body’s resistances, the virus may succeed in evolving a whole class of dissimilar strains simultaneously, analogous to making a number of chess moves at once, all over the board.

We assume that, as long as it is applied with enough tenacity, human reason must triumph (is fated to triumph) over other forms of purposive activity because human reason is the only form of reason there is, the only key that can unlock the codes by which the universe works. Human reason, we say, is universal reason. But what if there are equally powerful modes of “thinking,” that is, equally effective biochemical processes for getting to where your drives or desires incline you? What if the contest to see on whose terms warm-blooded life will continue on this planet does not prove human reason to be the winner? The recent successes of human reason in its long contest with virus thinking should not delude us, for it has held the upper hand a mere instant in evolutionary time. What if the tide turns; and what if the lesson contained in that turn of the tide is that human reason has met its match?

From the novel Diary of a Bad Year by J.M. Coetzee, published by Harvill Secker in 2007. (This excerpt is from pages 68 to 71 of the first hardback edition.) J.M. Coetzee is the winner of the Nobel Prize for Literature 2003.