Rationalism is a kind of builder’s bias which the impartial public cannot share; for the dead walls and glass screens which may have no function in supporting the roof are yet as needful as the roof itself to shelter and beauty. So the incidental filling of experience which remains unclassified under logical categories retains all its primary reality and importance. The outlines of it emphasised by logic, though they may be the essential vehicle of our most soaring thoughts, are only a method and a style of architecture. They neither absorb the whole material of life nor monopolise its values. And as each material imposes upon the builder’s ingenuity a different type of construction, and stone, wood, and iron must be treated on different structural principles, so logical methods of comprehension, spontaneous though they be in their mental origin, must prove themselves fitted to the natural order and affinity of the facts.[B] Nor is there in this necessity any violence to the spontaneity of reason: for reason also has manifold forms, and the accidents of experience are more than matched in variety by the multiplicity of categories. Here one principle of order and there another shoots into the mind, which breeds more genera and species than the most fertile terrestrial slime can breed individuals. [Sidenote: Complementary character of essence and existence.] Language, then, with the logic imbedded in it, is a repository of terms formed by identifying successive perceptions, as the external world is a repository of objects conceived by superposing perceptions that exist together. Being formed on different principles these two orders of conception—the logical and the physical—do not coincide, and the attempt to fuse them into one system of demonstrable reality or moral physics is doomed to failure by the very nature of the terms compared. When the Eleatics proved the impossibility—_i.e._, the inexpressibility—of motion, or when Kant and his followers proved the unreal character of all objects of experience and of all natural knowledge, their task was made easy by the native diversity between the concretions in existence which were the object of their thought and the concretions in discourse which were its measure. The two do not fit; and intrenched as these philosophers were in the forms of logic they compelled themselves to reject as unthinkable everything not fully expressible in those particular forms. Thus they took their revenge upon the vulgar who, being busy chiefly with material things and dwelling in an atmosphere of sensuous images, call unreal and abstract every product of logical construction or reflective analysis. These logical products, however, are not really abstract, but, as we have seen, concretions arrived at by a different method than that which results in material conceptions. Whereas the conception of a thing is a local conglomerate of several simultaneous sensations, logical entity is a homogeneous