The history of ideas is a field of research in history that deals with the expression, preservation, and change of human ideas over time. The history of ideas is a sister-discipline to, or a particular approach within, intellectual history. Work in the history of ideas may involve interdisciplinary research in the history of philosophy, the history of science, or the history of literature. In Sweden, the history of ideas and science (Idé- och lärdomshistoria) has been a distinct university subject since 6 November 1932, when Johan Nordström, a scholar of literature, was appointed professor of the new discipline in a ceremony at Uppsala University (coinciding with that commemorating the 300-year anniversary of the Battle of Lützen). Today, several universities across the world provide courses in this field, usually as part of a graduate programme.
The historian Arthur O. Lovejoy (1873-1962) coined the phrase history of ideas and initiated its systematic study in the early decades of the 20th century. Johns Hopkins University was a "fertile cradle" to Lovejoy's history of ideas; he worked there as a professor of history, from 1910 to 1939, and for decades he presided over the regular meetings of the History of Ideas Club. Another outgrowth of his work is the Journal of the History of Ideas.
Aside from his students and colleagues engaged in related projects (such as René Wellek and Leo Spitzer, with whom Lovejoy engaged in extended debates), scholars such as Isaiah Berlin,Michel Foucault, Christopher Hill, J. G. A. Pocock, and others have continued to work in a spirit close to that with which Lovejoy pursued the history of ideas. The first chapter of Lovejoy's book The Great Chain of Being (1936) lays out a general overview of what he intended to be the programme and scope of the study of the history of ideas.
Lovejoy's history of ideas takes as its basic unit of analysis the unit-idea, or the individual concept. These unit-ideas work as the building-blocks of the history of ideas: though they are relatively unchanged in themselves over the course of time, unit-ideas recombine in new patterns and gain expression in new forms in different historical eras. As Lovejoy saw it, the historian of ideas had the task of identifying such unit-ideas and of describing their historical emergence and recession in new forms and combinations.
The unit-idea methodology, intended to extract the basic idea within any philosophical work and movement, also has certain defining principles: 1) assumptions, 2) dialectical motives, 3) metaphysical pathos, and 4) philosophical semantics. These different principles define the overarching philosophical movement within which, Lovejoy argues, one can find the unit-idea, which can then be studied throughout the history of that idea.
Quentin Skinner criticizes Lovejoy's "unit-idea" methodology, and he argues that such a "reification of doctrines" has negative consequences. He emphasizes sensitivity to the cultural context of the texts and ideas being analysed. Skinner's own historical methodology is based on J.L. Austin's theory of speech acts. Andreas Dorschel criticizes Skinner's restrictive approach to ideas through verbal language, and points out how ideas can materialize in non-linguistic media or genres such as music and architecture.
Another important development within the study of ideas has been within the academic discipline of Intellectual History. The Harvard historian Peter Gordon explains that intellectual history, as opposed to the history of ideas practiced by Lovejoy, studies and deals with ideas within a broader context. Gordon further emphasises that intellectual historians, as opposed to historians of ideas and philosophers (History of Philosophy), "tend to be more relaxed about crossing the boundary between philosophical texts and non-philosophical contexts...[they regard] the distinction between "philosophy" and "non-philosophy" as something that is itself historically conditioned rather than eternally fixed." Therefore, intellectual history, as a means of reproducing a historically valid interpretation of a philosophical argument, tends to implement a contextualist approach when studying ideas and broader philosophical movements.
Michel Foucault rejects the idea of the traditional way historians go about writing, which is a narrative. He believed that most historians preferred to write about long periods of time instead of digging deeper into a more specific history. Foucault argues that historians should reveal historical descriptions through different perspectives. This is where he comes up with the term "archaeology" for his method of historical writing. His historical method differs from the traditional sense of historical writing and is divided up into four different ideas.
The first is that "archaeology" seeks to define the history through philosophical means, which is to say the discourse between thought, representation, and themes. The second is that, in "archaeology," the notion of discontinuity assumes a major role in the historical disciplines. The third idea is that "archaeology" does not seek to grasp the moment in history at which the individual and the social are inverted into one another. And finally the fourth point is that "archaeology" does not seek the truth of history, rather it seeks the discourse in it.