As a preliminary to the justification of equal opportunity, we require a few words on the concept. An opportunity is a chance to attain some goal or obtain some benefit. More precisely, it is the lack of some obstacle or obstacles to the attainment of some goal(s) or benefit(s). Opportunities are equal in some specified or understood sense when persons face roughly the same obstacles or obstacles of roughly the same difficulty of some specified or understood sort. In different contexts we might have different sorts of benefits or obstacles in mind. But in the current social context, and in the context of this discussion, we refer to educational and occupational opportunities, chances to attain the benefits of higher education and of socially and economically desirable positions, benefits assumed to be desired by many or most individuals, other things being equal. And we generally divide obstacles into two broad classes: those imposed by the social system or by other persons in the society, for example, the hardships of life in the lower economic classes or barriers from prejudices based on race, sex, or ethnic background; and those imposed by natural disabilities, for example, low intelligence or lack of talents.
The initial question is whether a moral society is obligated to create equality in opportunities in the senses just defined. I shall assume here initially that there is some such obligation on the part of society or the state, although I shall specify its nature and limits more precisely below. With the exception of certain libertarians, almost everyone, liberal and conservative alike, agrees in this assumption.