The combining imagination joined to the inductive spirit constitutes "the talent for invention strictly so-called," in industry, in the technique of science; it gives the artist and the poet the power of composing their works. The combining imagination plus the deductive spirit gives the speculative talent of the mathematician and philosopher; deduction predominates in the former, imagination in the latter.[78] FOOTNOTES: [78] Wundt, _Physiologische Psychologie_, 4th German edition, Vol. II, pp. 490-95. CHAPTER I THE PLASTIC IMAGINATION I By "plastic imagination" I understand that which has for its special characters clearness and precision of form; more explicitly those forms whose materials are clear images (whatever be their nature), approaching perception, giving the impression of reality; in which, too, there predominate _associations with objective relations_, determinable with precision. The plastic mark, therefore, is in the images, and in the modes of association of images. In somewhat rough terms, requiring modifications which the reader himself can make, it is the imagination that materializes. Between perception--a very complex synthesis of qualities, attributes and relations--and conception--which is only the consciousness of a quality, quantity, or relation, often of only a single word accompanied by vague outlines and a latent, potential knowledge; between concrete and abstract, the image occupies an intermediate position and can run from one pole to another, now full of reality, now almost as poor and pale as a concept. The representation here styled plastic descends towards its point of origin; it is an external imagination, arising from sensation rather than from feeling and needing to become objective. Thus its general characters are easy of determination. First and foremost, it makes use of visual images; then of motor images; lastly, in practical invention, of tactile images. In a word, the three groups of images present to a great extent the character of externality and objectivity. The clearness of form of these three groups proceeds from their origin, because they arise from sensation well determined in space--sight, movement, touch. Plastic imagination depends most on spatial conditions. We shall see that its opposite, diffluent imagination, is that which depends least upon that factor, or is most free from it. Among these naturally objective elements the plastic imagination chooses the most objective, which fact gives its creations an air of reality and life. The second characteristic is inferiority of the affective element; it appears only intermittently and is entirely blotted out before sensory impression. This form of the creative imagination, coming especially from sensation, aims especially at sensation. Thus it is rather superficial, greatly devoid of that internal mark that comes from feeling.