What Makes Something Abstract?

The likes of microbes, organs, asteroids, valleys, stones, and water are not metaphysically abstract.  Any such things that exist are physical objects or environments, though any logically necessary truths about them are abstract in nature since they are immaterial truths/existents grasped by the mind.  For instance, the fact that a brain or a boulder could not exist if there was something logically impossible about it is an abstract truth.  Possibility and impossibility are more foundational to reality than concrete examples of material objects because if a physical substance was truly impossible, it could never exist to begin with!  Possibility is dictated strictly by the laws of logic, starting with the axioms that cannot be false because then they would still be true.

One of these axioms is the fact that some things necessarily follow from others: if not, then it would be true in light of the nature of reality that there is nothing that logically follows from anything.  In other words, it would follow logically from the nature of reality that logical necessity is false!  This requires that logical necessity is true either way.  It would likewise follow from it being possible for contradictions to be true that it is impossible for the conflicting idea that contradictions are inherently impossible to be true.  Regardless, contradictions are impossible because their truth would still inescapably hinge on their falsity!  All genuine axioms are self-evident because they must be relied on in the process of disbelieving in them or as much as doubting them.

Something is, again, abstract if it is immaterial and grasped by the mind, such as a logical truth, a concept, or a mental state like a deep emotion, and logical axioms are the supreme foundation of these and all other things.  The mere physical existence of a mountain is not an abstract matter, or at least not apart from its relationship to issues of metaphysics and epistemology beyond its basic physical substance.  Is there an uncaused cause, and did it directly create the universe or create another being that bought the universe forth, and so on?  Is there any moral obligation to protect the natural world?  What makes the existence of mountains possible as opposed to impossible?  Can one know if a mountain exists rather than the mere mental image of it?  All of these issues are explicitly abstract.  How does a specific person subjectively feel about the sight of a mountain?  Even this is abstract, an issue of introspection and thus the mental realm of experience that is still necessarily governed by logic.

One major error is the idea that because a mind is necessary to grasp abstract "objects", they must exist because of or within minds; that is, they are not mind-independent.  Anyone is guilty of this extreme philosophical blunder who goes as far as to believe that logical axioms or mathematical truths are distinct from the material world but would not be true if there was no universe and no conscious beings.  This position neglects how logic is not only true of other things in that it necessitates certain truths about them, but it is true in itself, quite literally the entire reason anything is true at all.  Logic cannot be false and therefore necessitates itself, and consequently, it exists with or without any other existent, including God.

Logical truths are not thoughts, but a being with rational (rationalistic) thoughts does actively recognize logic for what it is: logical axioms are inherent truths that could only be false if they were still true, and other things follow necessarily from this handful of self-evident facts.  Discovering this entails making no assumptions and intentionally grasping the self-necessity and thus absolute certainty of logical axioms.  Even a person who believes in one thing that really does follow from another but does not know logical axioms, or rightly believes in logical axioms but makes assumptions regarding something else, is irrational.  As abstract as it is, for it is pure objectivity that transcends all else even while governing/underpinning the rest of reality, logic alone grounds knowledge, and it is logic alone that actually makes anything true.  Anything else can only be true if it is logically possible.