What follows is a quotation from A.C. Grayling's "Ideas that Matter" on the subject of equality:

"The idea of equality is a complex one. A general formulation of the ground for asserting equality as an ideal is this: there is no intrinsic feature of any indiviual or group which entitles them to preferential treatment in any respect over any other indiviual or group, or a greater share of any good than the share of any other individual or group. This way of putting equality's ground registers opposition to such views as that some are entitled to more or better than others because they are 'nobly born or racially superior, or some such.

Attempts to give a definition of equality quickly become problematic. 'Equality' unqualified does not make much sense; we need to specify the respect in which people are to be regarded as equal, or are to be treated equally. ... Contingent facts of history, geography, and biology mean that individual in different parts of the world and different tracts of time have very unequal standing points in the race for life's prizes. If absolute or unqualified equality is a practical impossibility, what can the ideal of equality apply to?"

(A.C. Grayling, "Ideas that Matter, 120-121.)