IMAGE-WORSHIP. 460 IMAM. (he recorded examples of the effect of tl>e mercy of CJod willi which it is associnloil in the minds of tlio fnitlifiil. In the Kastern cliurclies, cspe- tiully the Hiissian, great reverence is |)aiJ to |iriiit(>d pictures of llic saints, or representations in relief, called icons. Every lionse has one or more; and in the cliurclies the iconostnsis or screen which separates the sanctuary from the liody of the church is covered with thein. Stat- ues, except of the angels, are not used. The Kcfoniicrs generally rejected the use of images as an unM-riptural novelty, and stigma- tized the Catholic practice as superstitious, or even idolatrous. The Zwiiiglian and suhseiiuently the Calvinistic churches alisolutely and entirely leiiudiated all use of images for the purpose of worship. I^uther, on the contrary, while he con- demned the Roman worship of images, regarded the simple use of them, even in the church for the purpose of instruction and as incentive to faith anil devotion, as one of those iiuliU'erent things which may be permitted, altlimigh not of necessary institution. In the Lutheran churches of Germany and the northern kingdoms, pictures, crucifixes, and religious emblems are still freely retained. In all wholly Protestant communions images are entirely unknown, although their use has been freely revived in the Anglican com- munion of late years. Consult: l.iiiltke. Die llildi rvcrrhruiKj uiid hildlichcn Unrstcllungni in dm crslctt cliristlichcn Jiihrhiindirtoi ( Trci- burg, 1874) ; Hcfele, Conciliciigcschichtc (7 vols., il).. 18.54-71): Kraus, Roma sottcrranea (ib., 1870). IMAGINARY POINTS AND LINES. In analytic geometry, a point is said to be imag- inary if one or more of its coordinates are imaginary. K.g. the points of intersection of the straight line a- = (i and the circle a?' -|- y' = 4, found by solving the two equations, are x ■= 6, y := i V — 2, and (F =: 6, y = — 4 V — 2, the two values of i/ ( i.e. the ordinates of the points) being imaginary, the points of intersection of the given line and circle are said to he imaginary. Similarly, the conjugate axis of the hyperbola, (q.v. ) cuts the hyperbola in two imaginary points. A line whose equation contains imaginary coefTuients is called an imag- inary line. K.g. the asymptotes of an ellipse or circle are imaginary lines. Their equations may be obtained from the equations of the curves thus: l>et .r' -t- i/' = 0, then {x + yi) ix — yi ^ 0, and X + yi =: 0, x — i/i = are the imagi- nary asymptotes to the circle. Similarly, + ^- = then ■ and e+io^i-ro=«' a ' b ' a b ' are the imagiDary asymptotes to the ellipse. All of these imaginary lines have the real point a; = 0. V = 0. See Contimity. IMAGINARY QUANTITY. See Complex NfMBER. IMAGINATION (from T,at. imnginatio, from imaginari, to imagine, from imago, image). Taken in its broadest significance, thinking in images. In this sense it is synonymous with jiliantasy. Thus one may imagine a mountain, the sound of llowing water, the fatigue of a hing journey, the rhythmic march of an army, or the articulatory •feel" of a word in the throat. The piwcr to image, to imagine, is dependent, first of all, upon past exiK'rience. An individual born blind never has visual images; one born deaf never hears words "ringing in his head.' Moreover, the ability to image varies greatly Inim individual to imlividual. Visual images predominate in diie iniiiil, auditory in another, tactual or motor in a third. See Mk.iohv. In a more restricted sense, iiiiaginalion covers 11 single class of mental images. In this sigiiiti- <ance, "an imagination' is coordinate with a 'memory image' or an 'expectation image.' Taken as clusters of sensations, these three classes of images ar.; identical. They differ only in their reference and in their setting. A memory imago refers to some part of one's past ex|)i'rience (one has a visual image of one's childhood home, or an auditory image of a familiar piece of music). Its function is to 'reproduce' the past. Similarly, expectation images are set within the individual'a e|ierieme, but within the |iart that exists only in anticipation. Their function is to connect the present with the future. Finally, an iiiiagi- nation has no direct connection with the course of one's personal expcriemc. .s one reads a voluiiic of fiction, one may imagine scenes, voices, movements, situations. The whole narrative is held together by a succession of imaginations, or 'imagination images,' as they might be called. This is passive or reproductive imagination. Over against it stands active or constructive imagina- tion, an instance of which is furnished by the artistic productions of the jiainter and the sculp- tor. Between passive and active imagination there exists the .same diirercnce as between mus- ing and 'hard thinking,' In the passive type there is a nucleus — e.g. the text of the novel — about which are clustered various near-lying associations ; in the active type, images, more or less discrete and unrelated, are brought together and wrought into a systematic whole. The dif- ference is rather one of degree than of kind. -Active imaginations show greater selectiveness ; a disjunction of elements succeeded by an aggre- gation of those most fit to express some feeling or idea. This is evident in a painting of natural scenery, where the artist has modified nature to suit his purposes. .Tames Mill and Bain confine imagination to those constructions which are produced under the influence of emotion — e.g. ghosts and hob- goblins evoked by terror, or the creations of the poet and the musician. Sully, on the other hand, makes it cover three distinct forms of mental construction — cognitive imagination, practical imagination (or invention), and aesthetic (or poetic) imagination. Consult: rtain, The Senxea and the Intellect (London. 1888) : .lames. Principles of Psychology, vol. ii. (New York. 1890): Sully, Otltlines of Psycholnqt) (Xew York, 1891): Ambrosi, Psi- cologia drlV immaginn:irme (Rome, 1898) ; Hoef- ler, Psi/rhologie (Vienna, 1897). IMA'GO. The adult, sexually mature form of an insect which passes through metamorphoses. See Meta.mori'iiosis. IMAM, i^miim' (At. 'imam, leader, from 'omma, to lead, set an example) . The appellation
