noun. 
                    That philosophy which regards observation of fact as affording the only assurance of positive truth, as distinguished from mere mathematical truth; the philosophy which was naturally developed out of the prosecution of the experimental sciences; the school of English philosophy of Locke, Berkeley, Hartley, the Mills, and others, together with Hume.
                  
                
                  
                    noun. 
                    Experimental research in some branch of science.