He believed that the defining feature of voluntary behavior was that individuals have the ability to postpone a decision long enough to reflect or deliberate upon the consequences of a choice: "... the will in truth, signifies nothing but a power, or ability, to prefer or choose".
Han mente, at det, der definerer frivillig adfærd, er, at individer har evnen til at "udsætte" en beslutning længe nok til at kunne reflektere over dets konsekvenser: "...viljen betegner i sandhed intet ud over en kraft eller evne til at foretrække eller vælge".