This paper investigated the disagreement between Realists and Anti-realists on the observable and unobservable distinction in scientific practice. Whilethe realists maintain that machines and gadgets can simulate the human act of perception there-by making all realities under the screen of science observable, the anti-realists or the instrumentalists insist that what cannot be observed with the human senses even if detected with gadgets are not observable. This paper contended against the realist position which says that machines can simulate the human activity of perception. Hence the distinction between what is observable and unobservable is shown to be indisputable
