The nominalismo is a philosophical principle is based on that all that exists is individual, singular. This theory refutes the existence of the collective both inherently and transcendently. This word comes from the Latin "nomen" which means name.
Nominalism arose as a response to the conflicts of collectives or universals, specifically the following question arises, why do some things have the same pattern? that is, when placing as an example that a blouse, a wall and a clock are red, or that Socrates and Plato are men, it can be noted that the universal is repeated, that it can be included in several particulars at the same time, which It is the characteristic that relates several different elements such as the blouse, the wall and the clock, since they are all the same color and share the same universal, which in this case is the color red, and in the case of Socrates and Plato is that they are both men.
There are different forms of nominalism: Predicate nominalism, it is based on the fact that if a nominal has a characteristic X only if it is under the predicate X for example Plato and Socrates are men because the predicate "they are men" falls on both, this also implies a all qualities d similarity between objects, however this view is criticized because it does not provide a sufficiently clear solution to the problem of universals. Similarity nominalism, according to this theory a particular person has the characteristic X only if it is properly assimilated to a model of X, for example baseball and basketball will be sports only if the two are sufficiently similar.