Equality is a profound, multi-dimensional, and complex value. It may be regarded as an end in itself or it may be treated as a means to a higher end. All in all, equality is, and has to be, discussed along with its alternative connotations and purposes. Discrimination law literature does exactly that. In this research, I demonstrate that discrimination law invokes three concepts of equality, namely, equal treatment, equal dignity, and equality of opportunity, each of which also sets a purpose for discrimination law, and comes with alternative philosophical interpretations. The main question in this research is whether the European Courts rely on any particular philosophical interpretation(s) of the three concepts of equality; and, if they do, what are the legal contexts and consequences of their adoption of one interpretation or another? Each of the first three chapters of this research is designed in a threefold structure: The first portion describes the alternative interpretations of the respective concept of equality. It serves as a building block for the second portion, dedicated to the analysis of positive law, both at the statutory and case law levels, in Europe. The positive law portion reveals the philosophical interpretations of equality that are present in law. Thus, the second portions collectively constitute the heart of this research in law. The third portion emphasises the main lessons derived from the comparison of philosophical vis-à-vis legal references to equality and suggests how the two disciplines can continue to inspire each other. The fourth chapter tests the arguments developed in earlier chapters by critically examining existing and potential cases of environmental discrimination.