[substantial changes 3/20/19]
The psychule is a proposed model for the fundamental unit of the mind/sentience/consciousness. The term “psychule” is meant to be analogous to the term “molecule” as the fundamental unit of a substance, except that a psychule is not a substance but a process. Specifically, a psychule is a task/process/event as described by the Framework with a particular set of constraints on the Input and/or Mechanism and/or Output. What are those constraints? The answer is: it depends.
The constraints on a task/process/event that make it a psychule depend on the Philosopher asking the question. Some will require particular constraints, others will require additional constraints, and yet others may require alternate constraints.
Below is a hierarchy of levels of constraints. At the bottom level there are no constraints. At each higher level new constraints are added. I should point out that the choice of levels is not determinative, i.e., there could possibly be intermediary levels. I am simply choosing levels that seem to correspond to known theories of consciousness or are otherwise useful. Proponents of a given theory would, or should, designate a specific level as the psychule. At the appropriate level I will give my proposal for the psychule.
So here we go:
Level 1. No constraints. Associated theories: panpsychism, Hoffman’s Conscious Agent’s
Level 2. Mechanism was created to serve a purpose, such that Output serves as a valuable response to the Input. The “purpose” here could be natural, via natural selection, or it could be intentional, a goal created by a more advanced mind. Associated theory: Functionalism
Level 3. [Psychule] This level actually specifies (at least) a pair of coordinated tasks as part of the mechanism. The first task is a functional (level 2) task whose Output is a symbolic sign vehicle. (“Symbolic sign vehicle” is a term from Peirce’s Theory of Signs.) The “purpose” of this output is to be the input for a subsequent task, the Output of which is a valuable response to the object/referent of the symbolic sign. Associated theory: Integrated Information Theory.
Level 4. Same as level 3 with the addition that the Mechanism includes the ability to choose from among a large number of potential Inputs, and the symbolic sign vehicle can exist in multiple mutually exclusive states depending on the inputs. Associated theory: Global Workspace Theory
Level 5. Same as level 4 with the addition that the mechanism includes the ability to control the subset of inputs: Graziano’s Attention Schema,
Level 6. Same as level 4 or higher with the added constraints that the Output can become Input to the same Mechanism. HOT theories.
As indicated, I would designate level 3 as the psychule, mostly because I think at this level you can begin to explain qualia. I propose that a quale is best explained as a reference to the meaning of a symbolic sign as described in Level 3 above. I will expand on this in a subsequent post.
I should point out here that I do not (necessarily) ascribe “Consciousness” to the mechanism of a psychule. Instead, I ascribe Consciousness to a system which necessarily includes a mechanism capable of a psychule. The “consciousness of a system” is simply a reference to the psychules of which that system is capable. The system in question will include at least a mechanism, but may also include the environment of the mechanism, i.e., the substrates for the Inputs and Outputs.