This paper advertises a new account of computational implementation. According to the resemblance account, implementation is a matter of resembling a computational architecture. The resemblance account departs from previous theories by denying that computational architectures are exhausted by their formal, mathematical features. Instead, they are taken to be permeated with causality, spatiotemporality, and other non-mathematical features. I argue that this approach comports well with computer scientific practice, and offers a novel response to so-called triviality arguments.
Theories of ImplementationTheories of physical computation address two questions: Q1. What distinguishes physical systems that compute from those that don't? Q2. Among physical computing systems, what distinguishes those that compute the same thing from those that don't?(1) concerns the difference between laptops and calculators on the one hand, and rocks and tables on the other. (2), by contrast, concerns the distinction between one laptop computing dot products and another computing Fourier transforms. An adequate account of physical computation should answer both (Sprevak 2019).Different answers to Q1 and Q2 are possible. I shall be concerned with implementationist theories, which hold that a physical system computes if it implements some computational system, or 'computation', for short. Thus: 2 1 Draft of March 5, 2020. Word count: 4947. 2 What of alternatives to implementationism? On one reading, Piccinini's ( 2015) mechanistic account answers Q1 and Q2 by direct appeal to the notion of a computing mechanism. So construed, the implementation relation plays no part in the mechanistic account. This sort of approach is worth exploring, but is beyond the present scope.