Rules and resources enable people to do things, to make a difference in social world. Rules are written or unwritten laws or customs that guide or control behaviour or action. These rules can be found at the centre of Giddens's structuration theory. The concept of dualism is perceived in terms of two fundamental elements in existence in the world. In other words, it applies to any doctrine in which the fundamental forms of things, 'substances', 'reality', and so on, are seen as of two contrasting types without any possibility of one being reduced to the other. A sociological dualism is concerned with the reality as seen from two perspectives: individual agency and the structural determination of social outcomes. Socialist feminists focus on how the macro aspects of a society constrain women's options. Feminism's main aim of synthesising macro and micro orders is to give a picture of social organisation that combines economic activity with other forms of human social production.