IDEOLOGIA. — Etymologically (from ἰδέα ἐ λόγος), it is the science of ideas.
The term was first used by Destutt de Tracy: «L'idéologie est la science des idées (Éléments d'idéologie, I, Paris 1801, p. 5). Windelband nevertheless observes: «It is not impossible that de Tracy took this name from Fichte’s Wissenschaftslehre» (History of Philosophy, Italian translation by C. Dentice D'Accadia, II, Palermo 1938, p. 133, note). Destutt de Tracy understood i. as the study of representative mental facts, in their psychological origin and nature and in their expression through language. Given the prevalence, toward the end of the eighteenth century, particularly in France, of the psychological-descriptive approach (continuing the work of Condillac), philosophers in general were then called ideologues, and in particular, with a pejorative sense because of the abstractness that inspired their system, the group comprising Diderot, Cabanis, Volney, Helvetius, D'Alembert, etc.
In Italy the term was used by M. Gioia, B. D'Aquisto, F. Soave, P. Galluppi, A. Rosmini and others. For Galluppi, «i. is the science of the origin and generation of ideas» (Elements of Philosophy, II, Livorno 1852, ch. 1, § 1), and particularly of the ideas essential to the human intellect, that is, those ideas without which human knowledge would be impossible, such as, for example, substance, quality, space, number, cause, effect, body, self. For Rosmini, «i. treats of the origin and nature of ideas and therefore of being as pure and absolute idea, in which all the others are contained» (Theosophy, I, national edition, Rome 1938, p. 33). It is therefore the study of ideal being, that is, of the original form of thought: «I. is the science of the intellectual light by which man makes sensible things intelligible to himself, and from which he derives all knowledge..., i. does not create or invent this light..., but transfers it from the order of intuition to that of scientific reflection and thus forms a science of it» (Logic, I, cited edition, there 1942, p. 1, no. 1).
In Neoscholastic philosophy, the term was sometimes used, not without analogy to the Rosminian meaning, to indicate the psychological-gnoseological treatise on the origin and value of ideas or general concepts (cf. A. Farges-D. Barbedette, Philosophia neoscolastica, I, 63rd ed., Paris 1936, p. 369). But the usage has now almost disappeared. In current language, often with a tendency toward the pejorative sense, i. is equivalent to a philosophical system or set of principles and conceptions that characterize an epoch, an age, a culture, a people, or a group: e.g., spiritualist, materialist, liberal i. V. ILLUMINISMO; POSITIVISMO; SENSISMO.