I make use of computer science concepts in this commentary.
These concepts may help us understand the nature of mind, matter, space and time. (Please note that "class" and "instance" are terms used in the C++ programming language.)
Below, I present a rough "outline" of ideas:
-- A "class" C is a "specification" or "description" of a physical object O_1.
O_1 is an instance of the class C. Note: C can have several instances: O_1, O_2, O_3, etc., O_n.
C is not a physical object. However, the instances O_1, O_2, O_3, etc. are physical objects.
(Note: In the C++ programming language, a class is regarded as an "abstract entity." This entity describes a set of concrete instances.)
-- We can distinguish between the objective world (i.e., spacetime) and the subjective world (i.e., 3D, phenomenal space.) (See John Smythies' article "Space, Time and Consciousness": http://www.imprint.co.uk/pdf/smythies.pdf)
-- The objective world is made up of abstract classes. The subjective world is made up of concrete instances of these classes.
-- As we know, the objective world consists of entities such as chairs, tables, etc.
Let us consider a particular chair that exists in spacetime: "Chair_A." We can define "Chair_A_1" and "Chair_A_2" as two instances of the class Chair_A.
Suppose a person, Ann, wishes to observe Chair_A. She cannot observe this entity because it is a class. (As I've already indicated, a class is not a physical object). However, Ann can create an instance of Chair_A and then observe this instance.
Let us suppose that Ann creates the instance Chair_A_1. Chair_A_1 comes into existence inside Ann's subjective world as a 3D, phenomenal object.
Another observer, Betty, can create a different instance of the same Chair_A. She can create Chair_A_2. This instance is a 3D, phenomenal object that comes into existence inside Betty's subjective world.
-- Claim 1 (classical physics): The objective world is made up of concrete instances of physical objects.
Claim 2 (quantum physics): The objective world is made up of "possibilities" rather than "concrete instances of objects."
-- The object-oriented model (OOM) described above seems to be in accord with Claim 2 (i.e., the quantum description of reality). (In classical reality the objective world consists of concrete entities. However, in both quantum theory and OOM, the objective world consists of abstract entities.)
-- The object-oriented model seems to explain why the noumenal world cannot be directly observed by a mind. According to OOM, the noumenal world consists of abstract classes (i.e., "ACs") rather than concrete instances (i.e., "CIs"). As we know, ACs cannot be "observed" by a mind. (ACs are not physical entities; they are abstract specifications of physical entities.)
-- The process of observation can be understood as a process of instantiation. When one "observes" a physical entity, one creates a concrete instance of the entity.
-- The "present" is a subjective phenomenon associated with consciousness. When Ann creates the instance Chair_A_1, this instance acquires the property of being "present." (Chair_A_1 acquires "presentness" because Ann perceives this chair at her subjective "present.")
-- The class Chair_A does not exist inside any mind. This class therefore never acquires the property of being "present."
In order for an entity to be concretely real, the entity must have the property of being "present." Chair_A never has this property. Therefore, this class is never concretely real.
Classes in spacetime are not concretely real. (They lack the property of being "present.") However, instances of spacetime classes are concretely real. (They possess the property of being "present.")
-- "Chair_A" is a particular chair that exists in spacetime. "Chair_B" is another (particular) chair that exists in spacetime.
Chair_B_1, Chair_B_2, etc. are instances of the class Chair_B.
-- Spacetime is a four-dimensional entity. The class "Slice_A" is a particular 3D slice of spacetime. Slice_A_1, Slice_A_2, etc. are instances of the class Slice_A. (Note: The class "ST" can represent the 4D spacetime background.)
-- We can replace "spacetime" with the concept of "superspace." See Paul Davies' book Other Worlds: http://deoxy.org/superspace.htm
Reality can then be defined as having the following two components: 1) The objective world (i.e., superspace); and 2) The subjective world (i.e., 3D, phenomenal space).
-- "Slice(S)_A" is a particular 3D slice of superspace. "Slice(S)_A_1", "Slice(S)_A_2", etc. are instances of the class "Slice(S)_A".