Where something beautiful comes into existence, it always presents itself as the product of two mutually opposed but interrelated factors. On one hand, there is a looking, feeling subject, which belongs to the ideal world, and on the other hand, there is a looked, felt object, which is rooted in the real world. Strictly speaking, the beautiful is nothing other than the living current surging back and forth between subject and object, between the ideal and the real, in which the difference of the two is overcome. In the midst of their opposing relationship, they are felt as one and in this unity as the epitome of everything ideal and real, in short, as the unconditional, lackless being. Adolf Zeising is known above all as the founder and propagator of the doctrine of the Golden Ratio.