In the same way that Sigmund Freud created a way of making sense of the dynamics and passions of the human psyche, the pioneering French sociologist, Emile Durkheim, created a language for understanding our collective moral passions.

Like Freud, Durkheim was a secular Jew, committed to what he understood to be scientific methods of enquiry. Like Freud as well, Durkheim's "science" of moral life was intended not merely to generate abstract knowledge but had a broadly therapeutic intent. For Durkheim, the sociology of moral life played an important role in diagnosing social life, which for him carried over into his influential work in developing a curriculum for a secular moral education across the French school system. Working in the spirit of this Durkheimian project, the Yale cultural sociologist Jeffrey Alexander has referred to this as a "cultural psychoanalysis" through which we might become more aware of the myths and values that move our lives, for good and for ill.

Durkheim's first key move in analysing moral life was to locate it not in the private inner conscience of the superego, but in collective life. He understood the fundamental beliefs which shaped human life as essentially social phenomena. In his classic study, The Elementary Forms of Religious Life, published 100 years ago this year, Durkheim wrote that individuals who make up a social group "'feel bound to one another because of their common beliefs". Belief, as he argued, was not a matter of personal opinion or private religious experience, but "belongs to the group and unites it". For our highly individualised, post-reformation culture, in which we naturally think of belief in terms of deep inner conviction, Durkheim's perspective can be challenging. It draws us away from thinking about the inner authenticity of a person's beliefs to thinking about belief as a form of social practice. It opens up the possibility that, rather than being like a piece of software code that runs consistently in the mind of the individual, belief may be an intense but sporadic social experience dependent on particular kinds of group activity.

The second key move in his analysis of moral life was to argue that the most fundamental structure for human belief was the distinction between the sacred and the profane. A decade before completing The Elementary Forms, Durkheim had published a short book on Primitive Classification with his nephew, Marcel Mauss. In the conclusion, they argued that all early attempts by human cultures to categorise the world were ultimately organised in relation to a fundamental category of sacred things. Moreover, this human tendency to regard particular things as sacred persisted, albeit often in less obvious ways, in modern, scientific modes of thinking.

In The Elementary Forms, Durkheim developed this understanding of the sacred much further. Rather than simply being a particular way of making sense of the world, the sacred was something that evoked deep emotions in people, giving them a deep sense of moral energy and conviction. It was something experienced through special forms of collective action that drew groups together around a sacred object in ways that deepened people's sense of group identity and morality. Durkheim's sacred was not some kind of abstract reference to God, or a universal mystical presence. It was a living social reality, dependent on social interaction to charge it up as a powerful force, but which when energised could release a powerful, structuring influence on social life.

Why does this matter? Arguably, it is because Durkheim's work on the sacred offers the starting point for a public language for thinking about that which people take to be fundamental moral realities which exert an unquestionable claim over society. The concept of the profane can similarly help us to think about the role of symbolic representations of evil in social life. But to think about moral realities, such as deep convictions that one should not abuse a child or violate fundamental human rights, as norms produced through social practice can induce a particular kind of moral nausea. It seems to leave us prey to an empty moral relativism in which our deepest moral sentiments are reduced to transient social constructions.

Durkheim was no postmodern ironist, though, overturning the tapestry of social life simply to see how it had been threaded together. As we shall see in later posts in this series, he was a committed social and political activist, who believed that it was necessary to understand the deep moral forces of social life precisely so that these could be harnessed in constructive ways. The past century has given ample testimony of the power of these forces, inspiring not only civil rights protests and the global humanitarian movement, but also being used to legitimise totalitarian government and systematic genocide. By taking up Durkheim's intellectual project, we may begin to develop clearer ways of understanding the roots and forms of these powerful moral forces, as well as their enduring power in our lives today.