There are several reasons to study the work of thinkers who died long ago. First, these thinkers like Karl Marx, Emile Durkheim and Max Weber laid the foundation of sociology as a discipline. They are part of the classical tradition of sociology. Second, their ideas and insights have remained relevant even in the contemporary period. Third, studying them helps us understand how ideas about society develop, since ideas about society are themselves influenced by social conditions. They established important concepts like social facts, bureaucracy, and class conflict that continue to shape sociological understanding today.

There are also reasons to not study or critically approach these thinkers. First, these ideas have been subjected to criticism and may contain limitations or biases. Second, these ideas have undergone major modifications over time, suggesting that original formulations may be outdated. Third, since thinkers wrote in specific historical contexts like the Enlightenment or Industrial Revolution, their ideas may not fully explain contemporary social realities. For example, Durkheim's views on individual freedom in modern society may be questioned when mass communication standardises fashion and culture across different groups. Thinkers from earlier eras may have held views about 'primitive societies' or 'savages' that we now reject.