Philosophical/Psychological investigation.

Baby steps here, nothing profound..

Descartes said, 'I think therefore I am' (only in Latin an slightly more open to interpretation). As Hume would have it, nothing exists outside our minds, because we cannot prove otherwise - it's all in our imagination(s). Kant said a lot of things in such impenetrable language that it's hard to know, but I get the feeling he added the suggestion of a-priori ideas as the basis of human minds being separate from the world - not limiting the world. The world is definately there without a human to observe it, humans just add the classification of all things (like Plato's ideas).

Biologically, we know that the cells of a brain operate as a neural net. Making rudimentart neural nets in software, we know that they're damn good at pattern matching. So it's totally plausable to guess that the Platonic ideas are human patterns that are used to make sense of the world. Now, here's something that jumped to mind. Mpegs store movies as a single frame, followed by a number of changed to that frame, then another single frame followed by changes. Imagine our generic pattern as the frame, then add in changes to that frame to constitute a specific tree, or dog or whatever. This could be quite an efficient method of storing data (potentially a neural net would be very good at this too).