A question arises whether a person’s capacity is fit for two contrary acts, such as belief and disbelief, considered as possible choices.
The discussion affirms a common suitability for opposites at the level of underlying ability, while distinguishing the particular relation of power to the act that occurs. Someone’s choice of disbelief does not establish that they were utterly devoid of the ordinary means to choose belief.
When capacity is spoken of as directed to a particular act at a particular moment, that does not require treating the very essence of capacity as two unrelated substances, one for belief and another for disbelief.