ABSTRACT
In his treatise De natura locorum, written in the first quarter of the thirteenth century, Robert Grosseteste describes the operation of a round urine flask as a burning lens in terms of refraction of light rays at the surfaces of the flask resulting in focusing of the light to a point. In a challenging and controversial book, published in 1953, Arthur Crombie argued that Grosseteste laid the foundation of modern experimental science. In the treatise De iride, Grosseteste tells how refraction makes the image of an object appear in a different position if it is viewed through a transparent medium. One of Grosseteste's great contributions to scientific method is the enunciation of the principle of demonstration of the validity of a scientific hypothesis by the method of falsification. In the Commentary on the Posterior Analytics, Grosseteste also says: Sense apprehends singulars, wherefore the lack of a given sense means the incapacity to apprehend certain singulars.
