 His discoveries paved the way for a dramatic expansion to the capabilities of the surgeon; for his contributions he is often regarded as the father of modern surgery.These three crucial advances - the adoption of a scientific methodology toward surgical operations, the use of anaesthetic and the introduction of sterilised equipment - laid the groundwork for the modern invasive surgical techniques of today.In the late 19th century William Stewart Halstead (1852–1922) laid out basic surgical principles for asepsis known as Halsteads principles.