Duchamp is sometimes seen as a sociologist whose ideas are similar to the core ideas of the conservative ideology. For example, his concepts of social cohesion, social regulation, social consciousness, the role of the church or the functions of marriage. But Durkheim cannot be pigeonholed that easily. In his first major study, published in 1893, on the division of social labor, De la Division du Travail Social. A title, by the way, which reminds us of Mondefil and of Adam Smith, he presents an argument that is directed against the complaints of conservative and even romantic admirers of traditional societies. Durkheim says that in the societies of the past, everybody resembled everybody. People were similar and the similarity was, as it were, the social cement. Think of a medieval small city where everybody shares the same religion, where people are not yet highly specialized, they are not yet working in very different branches of the economic world because the division of labor is still in a very early stage. In such societies, he says, we see that they are glued together by mechanical solidarity. The individuals that constitute such a society are pretty identical, like the clogs in a large machine. Now conservatives complain that in modern societies that kind of cement is crumbling to pieces. And, in a way, Durkheim agrees, but it doesn't alarm him, because he says a new type of solidarity is now taking shape in front of our own eyes. Yes, it's true. People in modern societies are not very similar, any more. They believe in different gods. They have jobs that are so different that one craftsman doesn't have the slightest idea of what the other craftsman does. All of that is true, but it shouldn't lead us to believe that those people show a lower degree of solidarity. On the contrary, now they are bound together by a different kind of ties. The more people differ from one another, the more they need one another, the more they're dependent upon one another. The differentiation, the specialization between jobs, for example, professions, social functions, has reached such a high level that human beings, and groups of human beings, have become extremely interdependent now. They need one another, they cannot survive without each other. This is clearly not the old type of interdependence through similarity, it is more the opposite. It is interdependent through dissimilarity. Heterogeneity breeds interdependence. This is the social glue that Durkheim calls organic solidarity. In the great tradition of the organicist sociological thinkers like Herbert Spencer, Durkheim compares your societies with biological entities, with living bodies. In primitive organisms, the body parts may be very similar. But, in the higher organisms, the organs have differentiated to such a degree that the body as a whole can not survive unless those interdependent organs work together in a perfect fashion. We cannot think, we cannot have consciousness, you cannot understand this lecture without the oxygen the heart pumps through the stream of blood from the lungs into the brain. The differentiation of the organs in the bodies of the higher organisms has created new possibilities, but it also has created new vulnerabilities and that is the reason why the units within such a body are very interdependent. It is the reason why those well integrated organisms cannot survive if one of the vital organs doesn't work the way it should, and it is just the same with modern societies. They cannot survive if you take away, well for example, one professional group. Let's say all the school teachers, or all the train drivers. This organic interdependence is the new source of solidarity. The conservative thinkers who believe that the disappearance of solidarity through similarity is the reason why modern societies will fall to pieces have completely overlooked this important new source of solidarity. I have the impression that Duchamp wants to attract the attention of his audience here by using his terms in a known, intuitive fashion. Conservative thinkers had a tendency to describe traditional societies as organic wholes, where every part was related to every other part in a more or less natural way. And to describe modern societies as broken to bits and pieces by mechanical forces, the forces that dominate in the machine age. Now, Durkheim turns this whole terminology upside down. Traditional societies, he says, are kept together by mechanical solidarity, solidarity by similarity. Modern societies, on the other hand, by organic solidarity. Durkheim must have been an excellent teacher. Someone who knew that when you use your terms in a way that goes against the expectations of your listeners or of your readers, then they may be shocked out of their habitual ways of reasoning. And then they may pay attention to the unconventional insight that you want to convey.