[The history of color theories]. / Zur Geschichte der Farbenlehre.

The origins of color theories are closely linked to the Greeks' theories of vision. Plato explained vision as a combined action of light from within (i.e. from the eye) and light from without: this view was, in a certain sense, revived by Goethe. Aristotle, on the other hand, defined vision as the passive reception, by the eye, of an action originating in objects: thus, he was the originator of scientific optics, as propounded 2000 years later by Newton. The present author compares Newton's experimental analysis of spectral colors produced by triangular glass prisms with Goethe's more intuitive theory of the primordial phenomena (Urphänomene) of color vision. Apparently, Goethe started from the same point as Newton: experimentation with optical prisms. But he looked, as it were, in the opposite direction: he did not examine the objective image formed by a prism but described what he himself perceived when looking through a prism. It was this subjective image which he analyzed and on which he built his own color theory. The direction of his argument was fixed right from the beginning: from the very first glance through his prism he was convinced--by intuition, not by reflection--that Newton must have been wrong. No wonder this prejudice led him astray! However, Goethe's careful and skillful analysis of the subjective perception of light and colors bore other fruits. Under the heading of "physiological colors" he describes, in his "Farbenlehre", some important phenomena of visual physiology such as simultaneous and successive color contrasts.(ABSTRACT TRUNCATED AT 250 WORDS)

[Lessons from the history of therapy--therapeutic optimism and its pitfalls]. / Lehren aus der Therapiegeschichte--der therapeutische Optimismus und seine Tücken.

If we are to help patients effectively, our understanding of diseases and our therapeutic potential should, again and again, just be somewhat better than they actually are. Throughout the ages this has been the fundamental situation in medical practice. The response on the physician's part has nearly always been an attitude of therapeutic optimism. At all times physicians--and patients also--have relied on therapeutic principles and remedies based on professional experience and medical theory. In conjunction with the (generally recognized) healing powers of nature, and of (unrecognized) autosuggestion, this has led to many satisfactory and even remarkable cures. Examples from antiquity to the 19th century are quoted, and the snags of an over-optimistic attitude become evident, viz. a rational therapy is no better than the underlying pathogenetic theory; exaggerated therapeutic activity may cause useless torment to the patient (a point already made by Hippocrates); the optimistic physician or the enthusiastic pioneer of a new remedy may be blind to toxic side effects or the development of addiction. To sum up: therapeutic optimism is fine--but don't overdo it!