In an attempt to understand the origin of living systems we encounter the following problems: a) How can we conceive the origin of the first self-reproducing forms, and by means of what stimuli could commence a constant increase in the complexity of such forms? b) How can a translation apparatus for genetic information develop? One cannot imagine that such an apparatus for the synthesis of en­ zymes can function alone without the interference of enzymes them­ selves, which, however, could only become available after the construc­ tion of the apparatus itself. c) What stimulus mechanism is conceivable, that leads to the division of the genetic apparatus into a duplication system and an enzyme synthesis system? The main problem therefore is not the search for basic theoretical concepts. It is not a question which can be answered by means of a specific experiment. One should rather explore the principal possibilities of how molecules combine to produce more and more complicated func­ tional units. In trying to solve the puzzle of how the genetic apparatus is gradually built up as a complex aggregate of molecules one can draw up specific Denkmodels.