The general character of the artistic productions of man, the world over, shows that the style has the power of limiting the inventiveness of the productive artist; for, if we grant that potential genius like the one just described is born in all cultures, then the uniformity of art forms in a given tribe can be understood only by these limitations. The restriction of inventiveness is not due, as might perhaps be supposed, to the habit of copying old designs and to a sluggishness of the imagination of the artisan who finds it easier to copy than to invent. On the contrary, primitive artists hardly ever copy. Only in very exceptional cases are found working designs such as we employ in embroidery, dressmaking, woodcarving and architecture. The work is laid out in the mind of the maker before he begins and is a direct realization of the mental image. In the process of carrying out such a plan technical difficulties may arise that compel him to alter his intentions. Such instances can easily be discovered in the finished product and are highly instructive, because they throw a strong light upon the mental processes of the workman. We may see particularly in richly decorated basketry how such difficulties arise and what influence they exert upon the development of the design. Even in the making of mass products, like the pottery which we described before, (pp. 132 et seq.) copying is evidently not practised. The patterns are so simple and require only a small number of standardized movements which are combined in a variety of ways. The method of work corresponds strictly to our method of writing in which also a number of standardized movements occur in a multitude of combinations. Although the artisan works without copying, his imagination never rises beyond the level of the copyist, for he merely uses familiar motives composed in customary ways. It does not require much practice to learn how to carry out such simple work without patterns. The method of procedure is the same as that followed in European folk art. The embroidered or woven patterns, the wood carvings of European peasants are not copies of patterns but the results of individual composition. Pattern books appear only at a time when the folk art is decadent. Therefore, notwithstanding the rigidity of style it would be difficult to find two objects that have identical ornamentation. When designs are very complex, and rigid symmetry or accurate rhythmic repetitions are required, we find sometimes the use of stencils. It does also happen, that one person plans a design and another executes it. In these cases actual copying may occur; both of these instances are rare in primitive culture and do not modify the general picture as here outlined.