He is famous, or notorious, for having had a t-shirt printed with the slogan ‘<!g>Epistemology models <!g>Ontology’. However, the ontological indeterminacy of chaotic systems is very much open to question, given that the equations that model these systems are entirely <!g>deterministic (see God, Humanity and the <!g>Cosmos, pp133-35). <!g>Polkinghorne is well aware of this criticism, and has recently addressed it in Belief in God in an Age of Science (New Haven: Yale University Press, 1998) pp64-66. His point there is that the deterministic equations may in the end prove only to be approximations to the whole behaviour of such systems.