[Classification of diseases--is a systematic approach only possible at the expense of applicability?].

Classification of diseases is a practical tool in clinical and scientific medicine, but it is not free of problems. Using for example WHO's classification of diseases as a starting point, an example of the problems is given in the article, with reference to both methodological and philosophical points of view. It is suggested that pragmatic taxonomies with several dimensions, which would be useful for more than just a handful of clinicians, should be created. Subsequently, this type of classification can be revised in accordance with theoretical ideal requirements and considerations.