There are laws and explanations, reductive and emergent. There are descriptions and explanations of the Big Bang and of subnuclear particles and processes; there are mathematical abstractions; fiction; art; morality; shadow photons; parallel universes. To the extent that these symbols, images and theories are true – that is, they resemble in appropriate respects the concrete or abstract things they refer to – their existence gives reality a new sort of self-similarity, the self-similarity we call knowledge.
