To say that a man is sinful because he sins is to give an operational definition of sin. To say that he sins because he is sinful is to trace his behavior to a supposed inner trait. But whether or not a person engages in the kind of behavior called sinful depends upon circumstances which are not mentioned in either question. The sin assigned as an inner possession (the sin a person "knows") is to be found in a history of reinforcement.
B. F. SkinnerThe one fact that I would cry form every housetop is this: the Good Life is waiting for us - here and now.
B. F. SkinnerA culture must be reasonably stable, but it must also change, and it will presumably be strongest if it can avoid excessive respect for tradition and fear of novelty on the one hand and excessively rapid change on the other.
B. F. SkinnerThose who have had anything useful to say have said it far too often, and those who have had nothing to say have been no more reticent.
B. F. Skinner