Now, it is immediately obvious that what we think of as the extramental world cannot be interpreted as the product of conscious creative activity by the human mind. As far as ordinary consciousness is concerned, I find myself in a world of objects which affect me in various ways and which I spontaneously think of as existing independently of my thought and will. Hence the idealist philosopher must go behind consciousness, as it were, and retrace the process of the unconscious activity which grounds it.
But we must go further than this and recognize that the production of the world cannot be attributed to the individual self at all, even to its unconscious activity. For if it were attributed to the individual finite self as such, it would be very difficult, if not impossible, to avoid solipsism, a position which can hardly be seriously maintained. Idealism is thus compelled to go behind the finite subject to a supra-individual intelligence, an absolute subject.
The word 'subject' however is not really appropriate, except as indicating that the ultimate productive principle lies, so to speak, on the side of thought and not on the side of the sensible thing. For the words 'subject' and 'object' are correlative. And the ultimate principle is, considered in itself, without object. It grounds the subject-object relationship, and, in itself, transcends the relationship. It is the subject and object in identity, the infinite activity from which both proceed (Copleston p.4).I can agree with the German idealists up to this point, and I can see the appeal of German idealism as a system of philosophy that does not operate on the level of empirical science, and hence cannot really be refuted by such science. The danger arises when you get someone like Marx who, both understanding and believing wholeheartedly in the German idealism, develops a political philosophy that, once applied, resulted in (more or less) a series of disasters. In that regard, we have to value a Locke over a Marx. One can also see the appeal of logical positivism, which attempts to show that this sort of non-empirical thinking is actually meaningless nonsense. But, that project was doomed, as well. It makes a difference to us whether there is an infinite subject behind all of our perceptions or if they are the result of dead atoms and molecules. The different senses may be captured simply: the world is dead and stupid vs. the world is alive and intelligent. At root, from the perspective of apprehension theory, both of these statements are meaningless because one cannot predicate anything of the world as a whole, except perhaps a predicate of philosophical logic, such as "the world is that which has reference."