There are still other consequences when one follows Leonardo's dictum. Instead of acting and producing one just investigates. He who begins to divine the grandeur of the universe and its needs readily forgets his own insignificant self. When one is struck with admiration and becomes truly humble he easily forgets that he himself is a part of that living force, and that according to the measure of his own personality he has the right to make an effort to change that destined course of the world, the world in which the insignificant is no less wonderful and important than the great. Solmi thinks that Leonardo's investigations started with his art,[21] he tried to investigate the attributes and laws of light, of color, of shades and of perspective so as to be sure of becoming a master in the imitation of nature and to be able to show the way to others. It is probable that already at that time he overestimated the value of this knowledge for the artist. Following the guide-rope of the painter's need, he was then driven further and further to investigate the objects of the art of painting, such as animals and plants, and the proportions of the human body, and to follow the path from their exterior to their interior structure and biological functions, which really also express themselves in their appearance and should be depicted in art. And finally he was pulled along by this overwhelming desire until the connection was torn from the demands of his art, so that he discovered the general laws of mechanics and divined the history of the stratification and fossilization of the Arno-valley, until he could enter in his book with capital letters the cognition: _Il sole non si move_ (The sun does not move). His investigations were thus extended over almost all realms of natural science, in every one of which he was a discoverer or at least a prophet or forerunner.[22] However, his curiosity continued to be directed to the outer world, something kept him away from the investigation of the psychic life of men; there was little room for psychology in the "Academia Vinciana," for which he drew very artistic and very complicated emblems. When he later made the effort to return from his investigations to the art from which he started he felt that he was disturbed by the new paths of his interest and by the changed nature of his psychic work. In the picture he was interested above all in a problem, and behind this one he saw emerging numerous other problems just as he was accustomed in the endless and indeterminable investigations of natural history. He was no longer able to limit his demands, to isolate the work of art, and to tear it out from that great connection of which he knew it formed part. After the most exhausting efforts to bring to expression all that was in him, all that was connected with it in his thoughts, he was forced to leave it unfinished, or to declare it incomplete.