A preference for a simple model can mean either economy of assumptions or the convenience of accepting that model. Conflating these two meanings of simplicity turns a methodological principle into grounds for the premature exclusion of ontological alternatives.
Two Meanings of Simplicity
A psychologically simple model requires less effort to accept. Mass consciousness may gravitate toward it because it is less demanding in terms of energy. The search for truth, by contrast, often requires substantial cognitive effort.
Structural simplicity means fewer unnecessary assumptions while preserving explanatory power. The convenience of acceptance and the economy of assumptions belong to different levels, and neither establishes a model’s truth by itself.
The Scope of Occam’s Razor
Occam’s razor is a heuristic for economizing on assumptions. It applies when comparing models with equal explanatory power:
- There are at least two models.
- They explain the same set of facts.
- Under those conditions, preference is given to the model with fewer ontological commitments.
If one of the models fails to explain an essential part of a phenomenon, the condition of equal explanatory power has not been met. The existence of an explanatory gap, including in the matter of subjectivity, does not permit an alternative to be automatically excluded merely because it introduces additional assumptions.
An Explanatory Gap and the Choice of an Alternative
The statement “physicalism does not yet explain subjectivity” does not entail that the hypothesis of a soul is therefore correct.
The gap points to the incompleteness of the current explanation. Further progress may require an expansion of ontology or a reconstruction of the theory; choosing a particular solution requires its own independent grounds.
The hypothesis of a soul cannot be excluded in advance, but neither can it be declared necessary on the sole basis that another model is incomplete.
Methodology and Ontology
Methodological naturalism establishes an operating mode for scientific inquiry: to seek physical explanations first and foremost.
Ontological physicalism asserts that only the physical exists. This is a metaphysical position.
The working procedure of an investigation does not, by itself, establish the boundaries of being. Automatically downgrading an alternative to the status of an error requires separate justification and does not follow from the choice of method.
Symmetry of Initial Conditions
A comparison of ontological models requires:
- not assuming in advance that the physical is closed;
- not assuming in advance that an immaterial soul exists;
- registering the existence of subjective experience and its correlations with brain processes;
- comparing the explanatory grounds of competing models.
Such a comparison can include different versions of physicalism, dualism, panpsychism, neutral monism, and other approaches to the fundamentality of consciousness.
Necessary Complexity and the Multiplication of Entities
The criterion consists in distinguishing necessary structural complexity, which adds explanatory power, from excessive ontological commitments, which merely multiply entities.
Economy of assumptions retains its meaning when a comparison does not exclude part of the phenomenon under examination in advance. Competing positions must present their arguments on equal grounds.
