Federal law defines a "Disability" as a physical or mental impairment that substantially limits or restricts the condition, manner, or duration under which an average person in the population can perform a major life activity, such as walking, seeing, hearing, speaking, breathing, learning, working, or taking care of oneself. (An impairment or diagnosis, in and of itself, does not necessarily constitute a disability: it must "substantially limit" these activities. Disabilities do not necessarily impair the individual's performance but may require the individual to seek alternate methods of carrying out a given task.)