"To say that one practices zazen in order to become an enlightened person is like saying one practices medicine to become a doctor"

--- Thomas P. Kasulis, in Zen Action, Zen Person (1989), summarizing Dōgen:

In short, Dōgen rejects the view that zazen is a technique by which one comes to realization. Zazen is not the cause of satori; even at that first moment when the student begins to sit in meditation, zazen is already realization. Thus, in referring to enlightenment, Dōgen usually prefers to use the character shō (“authentication”) rather than satori (“realization”) or kaku (“awakening”). For Dōgen, proper sitting authenticates the enlightenment already there. Conversely, the student never reaches the point at which zazen is superseded. To say that one practices zazen in order to become an enlightened person is like saying one practices medicine to become a doctor. To practice medicine is to be a doctor. To practice zazen is to be enlightened. Enlightenment is not a static state of achievement; it is the active undertaking of the way exemplified in zazen.