And this involves the second purpose, that we shall try to study architecture as it actually evolved in practice. Remembering that it originated in the need of making provision for certain specific purposes, in a word, that its motive primarily was practical, moreover, that from the first it has been the product of invention, we will try to study it in relation to man’s gradual mastery of material and the processes of building. We will regard architecture in its fundamental significance as the science and art of building; tracing, as far as is possible, the stages by which man has met the problems imposed upon him by the purpose of the structure and by the conditions of the material available; how he gradually surmounted the difficulties of building, step by step improving upon his devices and processes and thereby creating new principles of construction, and, further, how the practical operations of one race and period were carried on, modified, or developed by other races, under different conditions and in response to differences of needs and ideals. And, while thus studying architecture as the gradual solution of practical problems of construction we will also keep constantly in mind the stages by which as man’s skill in building progressed, so also did his desire to make his structures more and more expressive of his higher consciousness of human dignity. How age after age built not only to meet the needs of living but also to embody its ideals of the present and the future life; how hand in hand with growing skill in workmanship was evolved superior achievement in artistic beauty. Our methods of study shall follow, as far as possible, the architect’s order of procedure. Given a site and the commission of erecting thereon a building for a specific purpose, the architect first concerns himself with the _plans_: the _ground plan_, and, if the building be of more than one story, the several _floor plans_. He lays out in the form of a diagram the lines that enclose the building and those that mark the divisions and subdivisions; indicating by breaks in the lines the openings of doors and windows and by isolated figures the position of columns or piers which he may be going to use for support of ceilings and roofs. The disposition of all these particulars will be determined not only by the purpose of the building, but also by the character of the site and by the nature of the materials and method of construction that the architect purposes to employ.