The Dialectical Moment: A Schema of the Adjacent Possible
Steven Johnson, an expert on creative geniuses and their ideas, has developed a concept which he calls the ‘adjacent possible’―roughly, the set of possibilities available with the resources and techniques of a given point in time. To illustrate, Gutenberg could not have built his printing press until a variety of minor inventions had been made, e.g. the wine press, which was the basis for his design. Johnson states that his concept provides a more cogent alternative to words such as zeitgeist, but it could be argues that much of the time the word zeitgeist is used, the ‘adjacent possible’ is the notion to which it refers.
G.W.F. Hegel is famous for his philosophy of history & the zeitgeist, as exemplified in his book The Phenomenology of Spirit. The most common interpretation of Hegel’s method was developed by Heinrich Moritz Chalybäus and popularized by Marx, with three stages: Thesis, Antithesis, Synthesis. (Hegel himself never used this terminology, and in fact disparages cold, rigid formulas in his preface to the Phenomenology, but Chalybäus’s formula works well enough that it has been preserved for over a century; nevertheless, the close reader of Hegel should bear the above in mind.) In the Thesis stage, an idea or historical stage (‘moment’) occurs. In the Antithesis stage, a historical moment occurs that is entirely opposite to that of the Thesis state. Finally, in the Synthesis stage, the contradictions of the Thesis & Antithesis stage are resolved (‘sublated’), and the Synthesis becomes the Thesis for a new Dialectical process.
The concept of the adjacent possible can be used to make sense of the famous quotation by Hegel, “What is real is rational, and what is rational is real.” There are many interpretations of the above quotation, which can seem deceptively simple. It might be clearer to think about this phrase as “What is thinkable is possible, and what is possible is thinkable,” the latter part referring to the adjacent possible: an idea becomes thinkable only after its conditions have made their way into the zeitgeist.
I have a rule that I’ve developed for myself regarding interpretation, however: the meaning of a quotation can only be fully expressed by the words that the author has used. Disregarding translation from the German, as well as textualism, the following answer emerges: Hegel wanted to emphasize the actualization of elements in the adjacent possible, and his use of the word ‘rational’ is peculiar to his own notion of ‘reason in history’.
**Note: This new emphasis by Steven Johnson on the possible strikes me as a Deleuzian twist to Hegel. Perhaps this betrays that Deleuze’s antagonism may have been brought on by ‘anxiety of influence‘ rather than simply disagreement.