There is a sense in which agency is a fundamental concept. Before we can talk about physics, we need to talk about metaphysics (what is a “theory of physics”? how do we know which theories are true and which are false?). My best guess theory of metaphysics is infra-Bayesian physicalism (IBP), where agency is a central pillar: we need to talk about hypotheses of the agent, and counterfactual policies of the agent. It also looks like epistemic rationality is inseparable from instrumental rational: it’s impossible to do metaphysics without also doing decision theory.
Does this refute reductionist materialism? Well, it depends how you define “reductionist materialism”. There is a sense in which IBP is very harmonious with reductionist materialism, because each hypothesis talks about the universe from a “bird’s eye view”, without referring to the relationship of the agent with the universe (this relationship turns out to be possible to infer using the agent’s knowledge of its own source code), or even assuming any agent exists inside the universe described by the hypothesis. But, the agent is still implicit in the “whose hypothesis”.
Once we accept the “viewpoint agent” (i.e. the agent who hypothesizes/infers/decides) as fundamental, we can still ask, what about other agents? The answer is: other agents are programs with high value of g (see Definition 1.6 in the IBP article) which the universe is “running” (this is a well-defined thing in IBP). In this sense, other agents are sort of like rocks: emergent from the fundamental reductionist description of the universe. However, there’s a nuance: this reductionist description of the universe is a belief of the viewpoint agent. The fact it is a belief (formalized as a homogeneous ultradistribution) is crucial in the definition. So, once again, we cannot eliminate agency from the picture.
The silver lining is that, even though the concept of which programs are running is defined using beliefs, i.e. requires a subjective ontology, it seems likely different agents inhabiting the same universe can agree on it (see subsection “are manifest facts objective” in the IBP article), so there is a sense in which it is objective after all. Decide for yourself whether to call this “reductionist materialism”.
There is a sense in which agency is a fundamental concept. Before we can talk about physics, we need to talk about metaphysics (what is a “theory of physics”? how do we know which theories are true and which are false?). My best guess theory of metaphysics is infra-Bayesian physicalism (IBP), where agency is a central pillar: we need to talk about hypotheses of the agent, and counterfactual policies of the agent. It also looks like epistemic rationality is inseparable from instrumental rational: it’s impossible to do metaphysics without also doing decision theory.
Does this refute reductionist materialism? Well, it depends how you define “reductionist materialism”. There is a sense in which IBP is very harmonious with reductionist materialism, because each hypothesis talks about the universe from a “bird’s eye view”, without referring to the relationship of the agent with the universe (this relationship turns out to be possible to infer using the agent’s knowledge of its own source code), or even assuming any agent exists inside the universe described by the hypothesis. But, the agent is still implicit in the “whose hypothesis”.
Once we accept the “viewpoint agent” (i.e. the agent who hypothesizes/infers/decides) as fundamental, we can still ask, what about other agents? The answer is: other agents are programs with high value of g (see Definition 1.6 in the IBP article) which the universe is “running” (this is a well-defined thing in IBP). In this sense, other agents are sort of like rocks: emergent from the fundamental reductionist description of the universe. However, there’s a nuance: this reductionist description of the universe is a belief of the viewpoint agent. The fact it is a belief (formalized as a homogeneous ultradistribution) is crucial in the definition. So, once again, we cannot eliminate agency from the picture.
The silver lining is that, even though the concept of which programs are running is defined using beliefs, i.e. requires a subjective ontology, it seems likely different agents inhabiting the same universe can agree on it (see subsection “are manifest facts objective” in the IBP article), so there is a sense in which it is objective after all. Decide for yourself whether to call this “reductionist materialism”.