Knowledge of nature is organized into two parts: Empirical and metaphysical; the former is performed by natural sciences, including physics, chemistry and biology, and the latter is done by purely rational research or philosophy. The cognitive idea of ​​the scientists in empirical natural sciences is to achieve natural laws since understanding the objects and their relationships and, ultimately, the recognition of the natural world and its major phenomena are not possible except by the laws of nature; however, it is an empirical task and one should refer to purely rational research to understand what the laws of nature are in general and what their components are and on which foundation of existence they are established. The present book is in line with this research goal and its content presents and examines two philosophical views to the laws of nature, called the viewpoint of the discipline and the viewpoints of universals. The translator examines and criticizes these two viewpoints and the other viewpoints not mentioned in the whole book but in the Introduction section.