An historical example of an analogy used by a scientist:
"The concept of infectious disease. This is based on the notion of the organism as a closed unit and of the hostile causative agents invading it. The causative agent produces a bad effect (attack). The organism responds with a reaction (defence). This results in a conflict, which is taken to be the essence of disease. The whole of immunology is permeated with such primitive images of war. …
It is very doubtful whether an invasion in the old sense is possible, involving as it does an interference by completely foreign organisms in natural conditions. A completely foreign organism could find no receptors capable of reactions and thus could not generate a biological process. It is therefore better to speak of a complicated revolution within the complex life unit than of an invasion of it."
Ludwik Fleck
Fleck, L. (1979). Genesis and Development of a Scientific Fact [Entstehung und Entwicklung einer wissenschaftlichen Tatsache. Einführung in die Lehre vom Denkstil und Denkkollektiv] (F. Bradley & T. J. Trenn, Trans.; T. J. Trenn & R. K. Merton, Eds.). The University of Chicago Press. (1935)
