With reference to architecture, it is true, generally speaking, that architectural forms have been developed through necessity, the function seeking and finding its appropriate form. For example, the buttress of a Gothic cathedral was developed by the necessity of resisting the thrust of the interior vaulting without encroaching upon the nave; the main lines of a buttress conform to the direction of the thrust, and the pinnacle with which it terminates is a logical shape for the masonry necessary to hold the top in position (Illustration 9). Research along these lines is interesting and fruitful of result, but there remains a certain number of architectural forms whose origin cannot be explained in any such manner. The secret of their undying charm lies in the fact that in them In and Yo stand symbolized and contrasted. They no longer obey a law of utility, but an abstract law of beauty, for in becoming sexually expressive as it were, the construction itself is sometimes weakened or falsified. The familiar classic console or modillion is an example: although in general contour it is well adapted to its function as a supporting bracket, embedded in, and projecting from a wall, yet the scroll-like ornament with which its sides are embellished gives it the appearance of not entering the wall at all, but of being stuck against it in some miraculous manner. This defect in functional expressiveness is more than compensated for by the perfection with which feminine and masculine characteristics are expressed and contrasted in the exquisite double spiral, opposed to the straight lines of the moulding which it subtends (Illustration 10). Again, by fluting the shaft of a column its area of cross-section is diminished but the appearance of strength is enhanced because its masculine character--as a supporting member resisting the force of gravity--is emphasized. [Illustration 9: CROSS SECTION OF BUTTRESS.] The importance of the so-called "orders" lies in the fact that they are architecture epitomized as it were. A building consists of a wall upholding a roof: support and weight. The type of the first is the column, which may be conceived of as a condensed section of wall; and of the second, the lintel, which may be conceived of as a condensed section of roof. The column, being vertical, is Yo; the lintel, being horizontal, is In. To mark an entablature with horizontal lines in the form of mouldings, and the columns with vertical lines in the form of flutes, as is done in all the "classic orders," is a gain in functional and sex expressiveness, and consequently in art (Illustration 11). [Illustration 10: CORINTHIAN MODILLION; CLASSIC CONSOLE; IONIC CAP]