marianne schneider has translated leonardo's words from the italian into german. she has also written the following text, which introduces the user to leonardo's intellectual universe.
the unerring gaze of passion
today the laws of visible nature and even those of invisible nature are being discovered; theoretically we know everything. so why should we turn to leonardo's writings and read how immense boulders can be tossed along by water?
nevertheless, let us read: "know that the stones can be tossed by water because water either flows around them on both sides or over them; if the water flows around the stone, then, after separating to stream past the stone, the water rejoins and digs away the heaped-up earth or sand before the stone; and when it has hollowed out enough of the ground in front of the stone, then the stone falls forward on its own. and if the water flows over the stone, then after it rises over the stone it falls vertically, and through the force of its impact it penetrates from the surface to the bottom of the remaining water and gnaws and washes away, carving out the support from under the stone, so that in this case too the stone tumbles forward on its own; and thus little by little it happens that the stone tumbles down the entire river. and if a smaller stone lies in front of the stone, then the water carves away the support for it in the same sequential order and does the same; and that is why the stones tumble in the bed of the flowing river.”
leonardo’s sentences lead our gaze under water and show us in detail what happens there: something that we are accustomed to classify as the phenomenon of erosion. but in delicate detail and with an undertone of amazement he describes how the visible world is composed and what makes up its movements, its changes.
"everything comes from everything, everything becomes everything, everything ends in everything. anaxagoras.” leonardo records without commentary this quotation from the pre-socratic philosopher. but he was one of the first, if not the very first, who suddenly noticed something unusual, namely a detail of the visible world, for example the mussel-shells in the mountains. starting from such a detail, he began to investigate and to discover that what had hitherto been taught and believed was false; and so he abandoned the prison house of the aristotelian world system, which had been upheld by the church and official philosophy, and which the natural sciences had sought to justify without ever casting a glance at the natural world.
but the tireless observer and chronicler of the most varied details never lost sight of the unity and overall interconnectedness of things, and still shows us today "the strange play of relations among things,” in which one world can be the mirror of another.