INNATISM. - A term of philosophical language, used to indicate any system or school that admits the original (congenital, innate) existence in the human spirit of concepts, categories, ideas not derived from experience. The term nativism is sometimes used in the same sense (and is indeed more common in the specific question of the origin of the ideas of space and time). In a broader sense, innatism may also indicate the existence of spontaneous dispositions in the human spirit.
Innatism represents, in its various forms, the historical antithesis of empiricism and sensism (q.v.), which, by reducing all contents of knowledge to mere data of experience, prejudice any true universality and necessity of human knowledge. It is precisely with the intent of providing a foundation for the universality and necessity of the concept (q.v.) that not a few forms of rationalism have believed they must seek its origin and derivation exclusively in the very nature of the spirit.
Innatism has historically taken various forms. In Plato (cf. Theaet., Resp., Tim.) the ideas are innate in the sense that they do not derive, as to their content, from the sensible world, but are posited as the immediate spiritual object of the intuitive reminiscence (ἀνάλυσις) of the soul. This form of innatism is accentuated in the conception of Plotinus and has a reflection in the epistemology of Augustine (q.v.), later continued, substantially, in not a few Scholastics, particularly in St. Bonaventure (q.v.).
In modern philosophy, Cartesian rationalism gave new vigor to innatism: already explicit in Descartes himself (cf. Medit., III), as a predetermination in the mind of concepts and principles, it is defended, in the sense of "virtual" pre-existence, by Leibniz (cf. Now. es., I, 3; II, 1) and, with Augustinian dependence, by Malebranche. In Kant the problem of the necessity and universality of knowledge determines his particular form of innatism, which understands the forms of knowing (intuitions and categories) as the a priori structure of the mind, a transcendent condition of experience itself (cf. De mundi sensibilis principiis, § 6, and Kritik der r. Vernunft, introd.). In later philosophy, among others, the position of Rosmini is to be recalled, according to which the idea of being is innate in the human intelligence as an immanent objectivity (cf. Nuovo saggio, sez. 5a, cap. 1, art. 8 and passim).
The positive instance of innatism, asserted against the insufficiencies of empiricism, lies precisely in the demand to preserve the character of necessity and universality of knowledge, which ensures the value of actual knowledge. If such universality cannot dispense with the original meaning of the intelligence as the power to think and affirm in the absolute order of being, it does not at all require that the contents in which thought is realized pre-exist in the spirit antecedent to experience. The true solution to the problem is to be sought in Thomistic realism, which posits in the objectivity of being, grasped in the real data of experience, the reason and the ontological principle of the universality and necessity of spiritual knowledge (q.V. CONCEPT; KNOWLEDGE; UNIVERSALS).