This is how science moves, through layers of history, through what phenomenologists call the “lifeworld.” The great scientist Benno Müller-Hill famously described the “two faces” of molecular biology. “In the textbooks, almost everything is solved and clear,” he wrote. “Most claims are so self-evident that no proofs are given. Old, classical experiments disappear.” In a sense, the first face is taken as a given. “The other face of molecular biology is seen at scientific conferences or read in recent issues or Nature, Science or Cell,” at the cutting edge of the field, where knowledge struggles with ignorance. Robert Pogue Harrison has suggested the metaphor of “two angels,” drawing on Paul Klee’s painting — made famous in Walter Benjamin’s “Theses on the Philosophy of History” — that depicts an “angel of history is borne upward through the air on outspread wings, facing backward.” In Benjamin’s vision, all the angel sees are “the accumulated ruins of the has-been.” Harrison goes on to suggest that
science flies on the wing of another kind of angel — the angel of neoteny — who weaves in and out of enfolded spaces, forever turning a corner or rounding a bend, entering or exiting a crease of the cosmos, such that his expectant, forward-looking gaze sees anew a world it has been seen countless times before, always as if for the first time.
–Jim Kozubek, On Writing a History of Crispr-Cas9