Seeing the Purple Elephant
Now, if that was Locke's view of ideas, the objections to it are so elementary and so obvious that it hardly needed a Berkeley to point them out. If sense perception simply consists of having ideas, which are alleged to be literal pictures, some accurate and other inaccurate, of inaccessible originals, there would be no justification for supposing that there were any originals at all, let alone for supposing that some of the pictures did resemble them but others did not, still less for claiming to be able to say which were the accurate pictures and which were not. On such a view there would be no explanation how it could occur to anyone that ideas were pictures of originals, and no reason whatever for his thinking so, even if he did. For the picture-original thesis to have any ground at all, there would have to be some occasion of experienceing an original, and some possibility of confronting picture with original; but of neither, on this view of Locke, could there be any possibility at all. The condition of his thesis being true would be precisely that we could have no possible ground for supposing it to be true, nor even rational explanation of one's entertaining it. It would be hard to understand why anybody should want to rate Locke as an important philosopher if his whole theory rests on errors so elementary that a first-year student in philosophy has no difficulty in spotting them.
A. D. Woozley, Introduction to John Locke, An Essay Concerning Human Understanding
Well, now, Professor, let's see:
If I were sitting in my screen-enclosed porch and saw a purple elephant go wheeling by and that was that, I might conclude that I had finally had that flashback I was promised all those decades ago.
But if I saw that elephant go wheeling by, and heard it trumpeting, and felt the thunder of its feet transmitted through the ground and porch, and, upon walking out into the yard, no doubt with eyes a-bulge, saw its footprints in the grass, and saw and smelled as well obviously fresh and steaming evidence of an elephant's passage, I would conclude that some idiot had been painting an elephant purple, and it got loose.
The concepts here, Professor, are induction, cross-comparison or -checking of senses, and exploration/experiment, all of which you surely have heard of before.
Would I flunk your first-year philosophy course over this, Professor?
And if not, what would that say about your no doubt keen first-year philosophy-student you so highly tout, and no doubt helped manufacture by the score?
The real problem here, perhaps, is that the questions in question are in fact questions of neurology, not philosophy or academic philosophastering, on which subject I have more to say here and here.
And if it's a matter of bandying non-neurological authorities on the nature of the world and our experience of it, Professor, I'll take Locke or Planck over Bishop Berkeley any time:
It is important to realize that the outside world is something independent from man, something absolute.
Me and Planck flunk again, I guess, Professor?
Keywords: academic bullshit, Berkeley, checking, comparison, elephant (purple), experiment, exploration, induction, Locke, neurology, perception, philosophastering, philosophy, Planck, real world, sensation, sensory transforms