Convergence

Generally speaking, many of the analogies observed between data that one is reluctant to bring together are qualified as fortuitous convergences. The concept of convergence was developed in particular by biologists concerned with classification, the taxonomists, in order to establish a hierarchy between the similarities observed, and to escape the illusions of a symbolic way of thinking, which would dream about superficial similarities. In astronomy, too, it took centuries to prove that there was no equivalence between the moon and the sun, despite their identical apparent diameter and their alternating illumination, which made them converge in the same category. Only those analogies that fall within similar causal series would be significant. If they fall under different causal series, their weight as a criterion for classification must be considered weak or non-existent.