Philip August Boeckh, writing around 1866, formulated the principle that the value of theory lies ‘in its capacity to bring unconscious activity to the level of consciousness’ (Mueller-Vollmer 1985, 133).
Practice is grounded in the unconscious or implicit functioning of theoretical precepts. The interpreter, insofar as she aims to explicate what functions implicitly in the act of writing, is more conscious of that meaning than the author can be (until the author turns from writing to interpreting what has been written). But of course the precepts guiding interpretation must function implicitly in order for the creative precepts to become explicit.
Interpretative talent is not developed by mechanical practice of hermeneutical precepts; these must rather, after they become vividly alive through actual interpreting, become so familiar through practice that one unconsciously observes them.… The author composes according to the laws of grammar and style, but is as a rule unconscious of them. The interpreter, however, cannot fully explain without consciousness of these laws. The man who understands must reflect on the work; the author brings it into being, and reflects upon his work only when he becomes as it were an expositor of it. The interpreter consequently understands the author better than the author understands himself.
— Boeckh (Mueller-Vollmer 1985, 139)
Gendlin might say instead that the reader carries forward the work of the author.