In this video (28’28’’) “What is Existence?” Stefan used an example of a tree as a concrete object and a forest as an abstract concept, which exists only in our head not in reality.
I’m quite bewildered with this explanation because e.g. in podcast #95 Stefan uses an example of rock as a concept and states: “concepts are mental organization of discrete sensual information based on common structure of atoms and matter”.
Moreover, even in this video (35’30’’) he states that concept is “when you take an attribute and extrapolate it to include all like instances” which I’m both happy with, but in that sense the tree is also a concept – “e.g. wooden plant with roots and treetop” but it exists in reality.
I understand that all concepts exist only in mind not in reality but there are concepts, which have its instances existing in reality like trees and those, which do not like forest or government.
So I would suggest dividing concepts into two groups those with concrete instances in reality (e.g. tree, rock) and those which have abstract instances (crowd, forest).
Any thoughts on that?