If one is dissatisfied with Luhmann’s social theory because he has relatively little to say about the material world, technology, the body, or ordinary human relations, we can turn to a theorist such as George Simmel, among many others (e.g., Latour, Foucault). Luhmann, however, said that Simmel sacrificed the concept of society:
Georg Simmel, who attributed this problem [operational closure of the psychic system] to modern individualism, preferred in the circumstances to sacrifice the concept of society rather than his sociological interest in individuals. Aggregate concepts, as he saw the problem, were questionable and should be replaced by relational theories. After all, he pointed out, astronomy was not a theory of the “starry sky.”Theory of Society, vol. 1, p. 7
No theory explains everything; therefore, one can piece together various theories to better understand what one is interested in.