Just as the coming to be of a substance may be described as either an extended process or the completion of an extended process depending on whether it is described as the coming to be of the composite or of the individual form, so the process of learning may be described as either an extended process or the completion of an extended process depending on whether it is described as the oscillation between states of truth and error or as the ‘settling down’ or cessation of this oscillation at the stage where knowledge has become a stable disposition (hexis). And again, the conflict dissolves if we take the extended process as the process by means of which the acquisition of knowledge as such comes about, and as the process that constitutes, but is not identical to this acquisition of knowledge.
Bowin, John F., "Aristotle on Learning in De Anima II.5" (2010). The Society for Ancient Greek Philosophy Newsletter. 381.