the study of organizational environments. Macrostructural theory of social structure Probably one of the biggest contributions Blau gave to sociology was his work in macrostructural theory. For him, social structure consisted of the networks of social relations that organize patterns of interaction across different social positions. During this time, many people had different definitions for social structure. Blau's definition, however, set him apart from the rest. For Blau, social structure did not consist of natural persons, but instead social positions. This meant that the "parts" of social structure were classes of people such as men, women, rich and poor. Blau believed that the root of social structure can be found whenever an undifferentiated group begins to separate itself along some socially relevant distinction. In Blau's eyes, one could not speak of social structure without speaking of the differentiation of people. He believes that it is these social distinctions along with some social characteristics (race, religion, age, gender, etc.) which determines who interacts with whom. His theory gave a more structured idea of "homophily" which describes the observation that people are drawn to others like themselves. This is because of structure although individuals may seem to have other interests but those are structurally produced as well. Blau coined the term "parameter of social structure" to refer to socially relevant positions that people could be classified as. Something could not be considered a parameter if it did not actually affect the social relations of individuals "on the ground". In his 1974 Presidential Address, "Parameters of Social Structure", Blau discussed two categories of parameters: graduated and nominal. For Blau, modern society was characterized by the fact that they were composed of (1) multiplicity of socially relevant positions and (2) that these positions were connected and sometimes in contradictory ways resulting in cross-cutting social circles. Two positions are contradictory if one interaction increase leads to interaction of another decreasing. Quotation One of his most famous quotations is: "One cannot marry an eskimo, if no eskimo is around". The stated "goal" of Peter Blau's work was: "An understanding of social structure on the basis of an analysis of the social processes that govern the relations between individuals and groups. The basic question ... is how social life becomes organized into increasingly complex structures of associations among men." Legacy Peter Blau played an important role in shaping the field of modern sociology and is one of