The article analyzes the implications of shifting from modernto a welfare state according with the definition of equality principle, then explains the consequences of promoting the non discrimination principle and its structure as surety element of free competition. On that basis, the author presents the main tools of non discrimination in European law and then gives details about three components of discrimination: “tracto, criterium and spatium”. Finally, the article explores the debate surrounding the notion of evidence when it is related to discrimination, emphasizing States duty on promoting equality in European law. / El artículo analiza las consecuencias del tránsito del Estado moderno al Estado de bienestar en la definición del principio de igualdad, paraposteriormente explicarnos las implicancias de la promoción del principio de no-discriminación y su configuración como factor de caución de la libre competencia. A partir de ello nos aproxima a los principales instrumentosdel derecho europeo de la no-discriminación, para seguidamente explicarnos detalladamente los tres componentes de la discriminación: tracto, criterium y spatium. Finalmente, aborda la problemática de la prueba en materia de discriminación y la obligación de promover la igualdad que tienen los Estados en el derecho europeo.

This investigation constitutes an attempt towards(1) understanding issues and problems relating to the notions of one, many, part and whole in Parmenides and Plato; (2) extracting conditions for a successful account of multiplicity and parthood;(3) surveying Deleuzian conceptions and uses of these notions; (4) appraising the extent to which Deleuze’s metaphysics can answer some of these ancient problems concerning the status of multiplicity and the nature of mereological composition, that is, of the relations that pertain between parts and the wholes that they compose.