 ‘Equality’ and ‘equal’ are incomplete predicates that necessarily generate one question: equal in what respect? (Rae 1980,p. 132 f.) Equality essentially consists of a tripartite relation between two (or several) objects or persons and one (or several) qualities. Two objects A and B are equal in a certain respect if, in that respect, they fall under the same general term. ‘Equality’ denotes the relation between the objects compared. Every comparison presumes a tertium comparationis, a concrete attribute defining the respect in which the equality applies – equality thus referring to a common sharing of this comparison-determining attribute. This relevant comparative standard represents a ‘variable’ (or ‘index’) of the concept of equality that needs to be specified in each particular case (Westen 1990, p. 10); differing conceptions of equality here emerge from one or another descriptive or normative moral standard. There is another source of diversity as well: As Temkin (1986, 1993, 2009) argues, various different standards might be used to measure inequality, with the respect in which people are compared remaining constant. The difference between a general concept and different specific conceptions (Rawls 1971, p. 21 f.) of equality may explain why some people claim ‘equality’ has no unified meaning – or is even devoid of meaning. (Rae 1981, p. 127 f., 132 f.)