Emile Durkheim, “the father of sociology,” is known for his early work on suicide among Protestants and Catholics in Europe, which was one of the first studies that used statistical methods (rather crude and primitive methods by today’s standards). He is also responsible for the term "social fact," and how these social facts, such as beliefs and customs, i.e. society’s rules, structures and institutions, have control and powers of coercion over us. The individual doesn’t acknowledge social facts exist until they violate a social norm and see that "social facts" are external, and control us. He refers to this realization as Sui Generis. Social facts are what hold society together and serve a function by creating rules or social order for all of us. Today, he is considered by sociologists to fall under the theoretical paradigm of Structural Functionalism.
Karl Marx was an economist, historian, and antecedent of conflict theory. His views of society were based on economics and the struggle between social classes. He viewed the economic system as a superstructure that is a dismal, predestined model of society that controls its members. He viewed social class as a class system of two distinct groups. The bourgeois, the “haves,” owned the means of production and capital. The proletariat, the “have-nots,” or the workers for the capitalist/industrialist, do not directly benefit from the fruits of their own labor. The goal of the capitalist is to reinvest and make more capital while employing the worker at the lowest possible wage. The laborer (worker) is a direct product of capitalism. Marx states a revolution of the proletariat against the bourgeois would be necessary for a classless society to evolve. He does not elaborate much in his work on how revolution will unfold, but I don’t think he would have advocated the violence of the communist regime in Russia years later. He believes in the necessary evils of capitalism to perpetuate and pave the way for the workers' class-consciousness in order to bring about social change and destroy capitalism. His shortcoming as a theorist is that he reduced the problems of society to an economic class conflict and didn't see the possibility of another solution.
Max Weber had a very pessimistic outlook for the future of the world, stating that eventually things would be so systematic and predictable we would turn into robots. There would be nothing spontaneous or unique; all life’s experiences would be superficial and lack meaning. He did not see modernity as a positive force but as a danger to the future and existence of society. With industrialization, capitalism and modernity, Weber’s work looks at a New World where religion, values, and the division of labor have changed the social order. Traditions, values and craftsmanship will eventually become obsolete. He called this change the rationalization of society and a "disenchantment of the world."
One of Weber's contributions to sociological research and inquiry is the term "verstehen," which means understanding in German; when studying the social world as sociologists, Weber says we must use this understanding to objectively study and consider the nature of a human being’s social actions.
Learn more about Max Weber here.