ABSTRACT
The role of diagrams in science has been evident since Euclid, and diagram use spans both theoretical and practical sciences, just like it covers natural, social, and humanity disciplines. This chapter focuses on the difference between diagrams and icons, and discusses the diagrammatic and iconic elements at work in the case of the watercolor painting of the bacterium Streptococcus pneumoniae. The prototypical diagram is a 2D graphical representation of some state-of-affairs, providing a skeletal selection of important relations within that state-of-affairs. Watercolor is an iconic medium in the sense that the hues rarely are exactly the same, which provide a watercolor painting with a more vibrant snapshot-like style than, for instance, standard, saturated focal colors. The beauty of watercolor shadings and complicated shapes may be aesthetically pleasing to our senses – just like the stylization of focal colors might be – but there also exists such a thing as the aesthetics of cognition or the aesthetics of knowledge.
