Modernism is a trend of thought that affirms the power of human beings to create, improve, deconstruct and reshape their environment, with the aid of scientific knowledge, technology and practical experimentation, and is thus in its essence both progressive and optimistic. The term covers many political, cultural and artistic movements rooted in the changes in Western society at the end of the nineteenth and beginning of the twentieth century. Broadly, modernism describes a series of reforming cultural movements in art and architecture, music, literature and the applied arts which emerged in the decades before 1914. But Modernism encouraged the re-examination of every aspect of existence, from commerce to philosophy, with the goal of finding that which was "holding back" progress, and replacing it with new, progressive and therefore better, ways of reaching the same end. In essence, the modernist movement argued that the new realities of the industrial and mechanized age were permanent and imminent, and that people should adapt their world view to accept that the new equaled the good, the true and the beautiful. Modern (quantum and relativistic) physics, modern (analytical and continental) philosophy and modern number theory in mathematics are, however, also said to date from this period.