Ability for capacity.Ability  is the power of doing; capacity  the faculty of receiving. “The ability  is in me to do him good.” “Man's capacities  have never been measured.”

ability , capacity : These words are not exactly synonymous in meaning when used in the singular. Ability is bodily or mental power; capacity is receptive or containing power. Ability when used in the plural embraces both meanings.

n. The natural equipment to accomplish some small part of the meaner ambitions distinguishing able men from dead ones. In the last analysis ability is commonly found to consist mainly in a high degree of solemnity. Perhaps, however, this impressive quality is rightly appraised; it is no easy task to be solemn.