In the light of his comments, let me try to clarify the subtlety. But there are limits on the properties that can be generated. Since each culture has its own conceptual reality that it believes in, its properties are real for it. In an epistemological view, the only limits on a conceptual model of the mind are the limits of imagination of the conceptualizing mind. For example, Angels, the Devil, any so-called phantasy, are all within the limits of a conceptual model of the world.
Different cultures hold wildly different conceptual models of the world.
Each human's experiential conceptual reality is distinct, but private. When sharing experience with others, those of the same belief system will claim 'real' what others in other belief systems hold to be phantasies. The point about generating experiential reality needs some amplification. The epistemological source, from which reality emerges as 'actuality', is a universal 'potentiality'. It is defined in terms of a process, the circular feedback process of experience of any organism with its environment.