Form (Lat. forma), in general, the external shape, appearance, configuration of an object, in contradistinction to the matter of which it is composed; thus a speech may contain excellent arguments,—the matter may be good, while the style, grammar, arrangement,—the form—is bad. The term, with its adjective “formal” and the derived nouns “formality” and “formalism,” is hence contemptuously used for that which is superficial, unessential, hypocritical: chap. xxiii. of Matthew’s gospel is a classical instance of the distinction between the formalism of the Pharisaic code and genuine religion. With this may be compared the popular phrases “good form” and “bad form” applied to behaviour in society: so “format” (from the French) is technically used of the shape and size, e.g. of a book (octavo, quarto, &c.) or of a cigarette. The word “form” is also applied to certain definite objects: in printing a body of type secured in a chase for printing at one impression (“form” or “forme”); a bench without a back, such as is used in schools (perhaps to be compared with O. Fr. s’asseoir en forme, to sit in a row); a mould or shape on or in which an object is manufactured; the lair or nest of a hare. From its use in the sense of regulated order comes the application of the term to a class in a school (“sixth form,” “fifth form,” &c.); this sense has been explained without sufficient ground as due to the idea of all children in the same class sitting on a single form (bench).
The word has been used technically in philosophy with various shades of meaning. Thus it is used to translate the Platonic ἰδέα, εἶδος, the permanent reality which makes a thing what it is, in contrast with the particulars which are finite and subject to change. Whether Plato understood these forms as actually existent apart from all the particular examples, or as being of the nature of immutable physical laws, is matter of discussion. For practical purposes Aristotle was the first to distinguish between matter (ὕλη) and form (εἶδος). To Aristotle matter is the undifferentiated primal element: it is rather that from which things develop (ὑποκείμενον, δύναμις) than a thing in itself (ἐνεργεία). The development of particular things from this germinal matter consists in differentiation, the acquiring of particular forms of which the knowable universe consists (cf. Causation for the Aristotelian “formal cause”). The perfection of the form of a thing is its entelechy (ἐντελέχεια) in virtue of which it attains its fullest realization of function (De anima, ii. 2, ἡ μὲν ὕλη δύναμις τὸ δὲ εἶδος ἐντελέχεια). Thus the entelechy of the body is the soul. The origin of the differentiation process is to be sought in a “prime mover” (πρῶτον κινοῦν), i.e. pure form entirely separate (χωριστόν) from all matter, eternal, unchangeable, operating not by its own activity but by the impulse which its own absolute existence excites in matter (ὡς ἐρώμενον, οὐ κινούμενον). The Aristotelian conception of form was nominally, though perhaps in most cases unintelligently, adopted by the Scholastics, to whom, however, its origin in the observation of the physical universe was an entirely foreign idea. The most remarkable adaptation is probably that of Aquinas, who distinguished the spiritual world with its “subsistent forms” (formae separatae) from the material with its “inherent forms” which exist only in combination with matter. Bacon, returning to the physical standpoint, maintained that all true research must be devoted to the discovery of the real nature or essence of things. His induction searches for the true “form” of light, heat and so forth, analysing the external “form” given in perception into simpler “forms” and their “differences.” Thus he would collect all possible instances of hot things, and discover that which is present in all, excluding all those qualities which belong accidentally to one or more of the examples investigated: the “form” of heat is the residuum common to all. Kant transferred the term from the objective to the subjective sphere. All perception is necessarily conditioned by pure “forms of sensibility,” i.e. space and time: whatever is perceived is perceived as having spacial and temporal relations (see Space and Time; Kant). These forms are not obtained by abstraction from sensible data, nor are they strictly speaking innate: they are obtained “by the very action of the mind from the co-ordination of its sensation.”