Intellectual history, or the history of ideas, is the study of the history of human thought and of intellectuals, people who conceptualize, discuss, write about, and concern themselves with ideas. The investigative premise of intellectual history is that ideas do not develop in isolation from the thinkers who conceptualize and apply those ideas; thus the intellectual historian studies ideas in two contexts: (i) as abstract propositions for critical application; and (ii) in concrete terms of culture, life, and history.