term:

Capacity

capacity n

pl: -ties
1 : a qualification, power, or ability (as to give consent or make a testament) created by operation of law
2 : an individual's ability or aptitude
;esp
: mental ability as it relates to responsibility for the commission of a crime (as murder) see also diminished capacity compare competency, incapacity, insanity

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.