Nick Wiggershaus

This thesis addresses the ontological status of computer programs. Previous studies have placed computer programs in almost every ontological category available and claimed that they have a ‘dual nature.' My primary contribution to the debate is offering an alternative framework emphasizing computational implementation and its relata. I argue that we do not need to endorse the dual nature view by suggesting that ‘program' is a polyseme - an umbrella term hosting various entities spanning the abstract-concrete dichotomy. The advantage of this view is the avoidance of positing metaphysically dubious entities. Instead, we can understand the ontology of programs as a network of relations between abstracta and concreta that we bundle together through implementation when using computing machines as epistemic tools. To flash out and explore the claims of this alternative view, I first delve into the philosophical literature on implementation and taxonomize its different notions. In due course, I offer a unified theory of agential implementation, short UTAI. Specifically, UTAI advocates developing a series of related clarificatory case studies that track three different dependency relations between us and the ontologically different constituents under the term program. Accordingly, I discuss the implications of the first dependency relation between programmers and programs as abstract objects. By adopting the Problem of Creation - a well-known issue from the philosophy of art - I present a fresh perspective on the metaphysical options that allow us to view programs as abstract entities. Next, I focus on the second dependency relation between human agents and physical computation. As a result, I provide a new argument for understanding computational implementation as a three-place relation and develop a suitable notion called Implementation-as (based on the DEKI account of scientific representation). Lastly, I address the third dependency relation between programmers and the material systems used for program execution. By combining the insights of interventionism, technical artifacts, and neo-mechanistic literature, I introduce the notion of ‘physical programmability.'

This article delivers an account of what it is for a physical system to be programmable. Despite its significance in computing and beyond, today’s philosophical discourse on programmability is impoverished. This contribution offers a novel definition of _physical programmability_ as the degree to which the selected operations of an automaton can be reconfigured in a controlled way. The framework highlights several key insights: the constrained applicability of physical programmability to material automata, the characterization of selected operations within the neo-mechanistic framework, the understanding of controlled reconfiguration through the causal theory of interventionism, and the recognition of physical programmability as a gradual notion. The account can be used to individuate programmable (computing) systems and taxonomize concrete systems based on their programmability. The article closes by posing some open questions and offering avenues for future research in this domain.