One idea from (broadly) contemporary science which had captured both the attention of the media and (therefore?), to some degree, the general public is chaos theory, receiving a popular presentation in the novel Jurassic Park (Crichton 1991) and in the large-grossing film of the same title (1993). It presents a popular view that contemporary science is no longer deterministic in the way it had seemed in the past (and as I presented it here); the (assumed) conclusion that the world was somehow chaotic might seem to undermine the determinist's whole position, not least, by undermining the first premise of the argument (Chapter 2, p. 21).

As a preliminary, no substantial conclusion should be drawn from the name alone: do the assumptions and practices of chaos theory indeed suggest that the world is chaotic? As we will find, they do not! (The name “chaos theory” is just a name.)

There are two distinct (but related) threads within chaos theory. The first concerns its most famous thesis, the butterfly effect, or the thesis of “sensitive dependence on initial conditions” (Gleick 1987: 8). Suppose we wish to predict where a cannon-ball will fall to earth. If we genuinely knew the relevant causal laws (say, those relating to gravity, to air-resistance, to the mechanism of the cannon, and the like) and the relevant initial conditions (exact weight of the cannon ball, exact charge in the shell, exact wind conditions, etc.) we could predict exactly the cannon-ball's landing point. Of course, we typically do not know these things. We know at best some aspects of them, more and less exactly.