This passage is from Goethe's celebrated novella Elective Affinities (1809), where it serves the narrative function of signalling the moment when the link between the title and the central theme of the story becomes explicit. In this part of the story, the subject of discussion between a married couple and their male guest is the meaning of the term ‘affinity’. The guest explains that the term refers to the phenomenon in chemistry and physics where substances (such as water, oil or quicksilver) tend to ‘adhere to themselves’, and even if they are forcibly separated they slide back into each other and create a unity as soon as the external force is removed. By contrast, other materials, such as oil and water, refuse to combine even with force applied. The character of Charlotte observes that the same may be said of social circles, such as where members of certain classes and professions tend towards each other but are repelled by members of other groups. There ensues a discussion of the likeness of these chemical and social tendencies, including the fact that substances that repel one another can be brought together with a mediating substance (as with alkaline salt in the case of oil and water), just as laws and customs can bind together socially disparate individuals.

Observing the likeness between chemical and human activity is, of course, not merely a case of mistaken metaphor or the egotistical projection of human personality on to inanimate objects, as the character of Eduard suggests in the quotation above. Rather, it intimates two claims that will become important for our discussion below. The first is that substances not only come together as a partnership, but rather that in coming together they relinquish the differences that make them individual. An example might be when a raindrop joins a puddle, or when later in Goethe's story the characters of Eduard and Ottilie begin to exhibit the same handwriting, the same idiosyncrasies in musical performance and simultaneous thought processes – they come to mirror each other so closely that it seems as if they were a single character.