I consider then, that generally speaking, to render a reason of an effect or Phaenomenon, is to deduce It from something else in Nature more known than it self, and that consequently there may be divers kinds of Degrees of Explication of the same thing. For although such Explications be the most satisfactory to the Understanding, wherein 'tis shewn how the effect is produc'd by the more primitive and Catholick Affection of Matter, namely bulk, shape and motion, yet are not these Explications to be despis'd, wherein particular effects are deduc'd from the more obvious and familiar Qualities or States of Bodies...For in the search after Natural Causes, every new measure of Discovery does both instinct and gratifie the Understanding.