EXPERIENCE.—From *experimentum* (I try, I test), it is, in a generic sense, every perception of contents and data of consciousness (v.), and therefore every modification and determination of the conscious life of the self; in an objective sense, the total complex of conscious phenomena. According to the specific diversity of these, the self is also subdivided into various species, assuming more determinate references. It is called external experience when it is the perception of all contents of knowledge given as external to the subject, while it is internal when it refers to phenomena and subjective states (acts and functions of psychic life); it is sensible if it has as its object the data proper to sensibility, and spiritual if it concerns the data and contents of intellectual and volitional life. One also speaks of religious (v.), artistic, etc., experience, meaning particular states of consciousness in which phenomena of a religious, artistic, etc., order are lived, which determine corresponding psychological situations, more or less profound and permanent, in the subject. This usage approaches the common sense of experience, which refers to the acquisition of habitual, objective, and certain knowledge through a repeated series of lived situations, to experience (cf. life experience; V. personal experience).
In a narrower sense, already in use since antiquity and especially valued in modern philosophy, it is the direct, concrete, and positive knowledge of the sensible world, of its phenomena, and of their laws, by means of observation and experiment. As such, experience is contrasted with rational and a priori knowledge, which develops general principles through a purely logical-synthetic process. In this latter sense, experience constitutes the basis of the analytic-inductive method (v. ANALYSIS) and is indispensable for objective knowledge, and thus also for an objective philosophical interpretation of nature.
In the history of philosophy, one can discern a recurring oscillation of gnoseological-metaphysical systems, depending on the different evaluation of experience. Understood especially in the last sense indicated, in Greek philosophy experience is overvalued by Heraclitus, neglected by Platonic rationalism, while it regains its natural scientific function in Aristotle as the means and path by which human intellect ascends from the particular to the knowledge of the universal (cf. *Met.*, I, 1; *Phys.*, VII, 3). In the main currents of medieval Scholasticism, especially in St. Albert the Great and St. Thomas Aquinas, and later in Roger Bacon, the scientific-philosophical function of experience is expressly recognized, whereas it was often forgotten by the exponents of late Scholasticism. In modern philosophy, experience, inculcated by F. Bacon and scientifically promoted by Galileo, is proclaimed the sole source of knowledge by empiricism and phenomenism (Locke, Hume, Stuart Mill), down to the denial of any achievement of thought that claims to be an essential surpassing of the data directly presented by experience itself. In Kant, experience, posited as the subjective synthesis of external impression and transcendental intuition of sensibility, loses its ancient value as objective knowledge: a position taken up and accentuated by modern scientific relativism. In the most recent idealistic systems, one returns to the a priori method and to the devaluation of experience, which, though not denied, is forcibly confined within absolute theoretical schemes independent of experience itself.