The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and of the effects that prevailing ideas have on societies. It is not a specialized area of sociology but instead deals with broad fundamental questions about the extent and limits of social influences on individuals' lives and with the social-cultural basis of our knowledge about the world. Complementary to the sociology of knowledge is the sociology of ignorance, including the study of nescience, ignorance, knowledge gaps, or non-knowledge as inherent features of knowledge-making. The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and of the effects that prevailing ideas have on societies. It is not a specialized area of sociology but instead deals with broad fundamental questions about the extent and limits of social influences on individuals' lives and with the social-cultural basis of our knowledge about the world. Complementary to the sociology of knowledge is the sociology of ignorance, including the study of nescience, ignorance, knowledge gaps, or non-knowledge as inherent features of knowledge-making. The sociology of knowledge was pioneered primarily by the sociologist Émile Durkheim at the beginning of the 20th century. His work deals directly with how conceptual thought, language, and logic can be influenced by the societal milieu out of which they arise. In an early work co-written with Marcel Mauss, Primitive Classification, Durkheim and Mauss study 'primitive' group mythology in order to argue that classification systems are collectively based and that the divisions within these systems derive from social categories. Later, Durkheim in The Elementary Forms of the Religious Life would elaborate his theory of knowledge, examining how language and the concepts and categories (such as space and time) used in logical thought have a sociological origin. While neither Durkheim, nor Mauss, specifically coined nor used the term 'sociology of knowledge', their work is an important first contribution to the field. The specific term 'sociology of knowledge' is said to have been in widespread use since the 1920s, when a number of German-speaking sociologists, most notably Max Scheler and Karl Mannheim, wrote extensively on sociological aspects of knowledge. With the dominance of functionalism through the middle years of the 20th century, the sociology of knowledge tended to remain on the periphery of mainstream sociological thought. It was largely reinvented and applied much more closely to everyday life in the 1960s, particularly by Peter L. Berger and Thomas Luckmann in The Social Construction of Reality (1966) and is still central for methods dealing with qualitative understanding of human society (compare socially constructed reality). The 'genealogical' and 'archaeological' studies of Michel Foucault are of considerable contemporary influence. The Enlightenment movement ought not to be underestimated in its influence upon the social sciences. When these philosophers worked towards a scientific analysis of society, they were engaged in a sociology of ideas and values, albeit their own commitment was to critical rationalism. The Enlightenment strove for progress, change, secularism, but above all, to freedom, the freedom for individuals to decide their own fate. There was a commitment to practical science with humankind at the centre (as opposed to God or gods) and this is the real source of social science. This new science was not interested in revealed knowledge or a priori knowledge but in the workings of humanity: human practices, and social variety and regularities. Western thought, therefore, received a significant movement towards cultural relativism, where cross-cultural comparison became the dominant methodology. Importantly, social science was created by philosophers who sought to turn ideas into actions and to unite theory and practice in an attempt to restructure society as a whole. Sociology of knowledge requires a certain viewpoint which was first expounded by Giambattista Vico in his New Science, written in the early 18th Century, a great deal before the first sociologists study the relationship between knowledge and society. In this book, a justification for a new historical and sociological methodology, the main point is that the natural world and the social world are known in different ways. The former is known through external or empirical methods, whilst the latter can be known internally as well as externally. In other words, human history is a construct. This creates a key epistemological distinction between the natural world and the social world which is a central concept in the social sciences. Primarily focused on historical methodology, Vico asserts that in order to study a society's history it is necessary to move beyond a chronicle of events by examining the cultural elements of the society, what was termed the 'civil world'. This 'civil world', made up of actions, thoughts, ideas, myths, norms, religious beliefs, and institutions, is the product of the human mind. Since these elements are socially constructed, they can be better understood than the physical world, understood as it is in abstraction. Vico highlights that human nature and its products are not fixed entities and therefore necessitate a historical perspective which emphasizes the changes and developments implicit in individuals and societies. He also emphasizes the dialectical relationship between society and culture as key in this new historical perspective. Vico's ideas, whilst permeated by his own penchant for etymology, and a theory of cyclical history (corsi e ricorsi), are significant nonetheless for the underlying premise that our understanding and knowledge of social structure is dependent upon the ideas and concepts we employ and the language used. Vico, mostly unknown in his own time, was the first to establish the foundations of a sociology of knowledge even if his concepts were not necessarily picked up by later writers. There is some evidence that Montesquieu and Karl Marx had read Vico's work. However the similarities in their works are superficial, limited mainly to the overall conception of their projects, characterised by cultural relativisim and historicism. Émile Durkheim (1858–1917) is credited as having been the first professor to successfully establish the field of sociology, institutionalizing a department of sociology at the Université de Bordeaux in the 1890s. While his works deal with a number of subjects, including suicide, the family, social structures, and social institutions, a large part of his work deals with the sociology of knowledge. While publishing short articles on the subject earlier in his career (for example the essay De quelques formes primitives de classification written in 1902 with Marcel Mauss), Durkheim's definitive statement concerning the sociology of knowledge comes in his 1912 magnum opus The Elementary Forms of Religious Life. This book has as its goal not only the elucidation of the social origins and function of religion, but also the social origins and impact of society on language and logical thought. Durkheim worked largely out of a Kantian framework and sought to understand how the concepts and categories of logical thought could arise out of social life. He argued, for example, that the categories of space and time were not a priori. Rather, the category of space depends on a society's social grouping and geographical use of space, and a group's social rhythm that determines our understanding of time. In this Durkheim sought to combine elements of rationalism and empiricism, arguing that certain aspects of logical thought common to all humans did exist, but that they were products of collective life (thus contradicting the tabula rasa empiricist understanding whereby categories are acquired by individual experience alone), and that they were not universal a priori truths (as Kant argued) since the content of the categories differed from society to society. Another key elements to Durkheim's theory of knowledge is his concept of représentations collectives (collective representations), which is outlined in The Elementary Forms of the Religious Life. Représentations collectives are the symbols and images that come to represent the ideas, beliefs, and values elaborated by a collectivity and are not reducible to individual constituents. They can include words, slogans, ideas, or any number of material items that can serve as a symbol, such as a cross, a rock, a temple, a feather etc. As Durkheim elaborates, représentations collectives are created through intense social interaction and are products of collective activity. As such these representations have the particular, and somewhat contradictory, aspect that they exist externally to the individual (since they are created and controlled not by the individual but by society as a whole), and yet simultaneously within each individual of the society (by virtue of that individual's participation within society).