In strong opposition to methodological naturalism in the field of sociology, historicism claims that some of the characteristic methods of physics cannot be applied to the social sciences, owing to the profound differences between sociology and physics. Physical laws, or the ‘laws of nature’, it tells us, are valid anywhere and always; for the physical world is ruled by a system of physical uniformities invariable throughout space and time. Sociological laws, however, or the laws of social life, differ in different places and periods. Although historicism admits that there are plenty of typical social conditions whose regular recurrence can be observed, it denies that the regularities detectable in social life have the character of the immutable regularities of the physical world. For they depend upon history, and upon differences in culture. They depend on a particular historical situation. Thus one should not, for example, speak without further qualification of the laws of economics, but only of the economic laws of the feudal period, or of the early industrial period, and so on; 5always mentioning the historical period in which the laws in question are assumed to have prevailed.