Some defenders of Warren-style arguments grant that these problems have not yet been fully solved, but reply that the "natural capacities" view fares no better. It is argued, for example, that as human beings vary significantly in their natural cognitive capacities (some are naturally more intelligent than others), and as one can imagine a series or spectrum of species with gradually diminishing natural capacities (for example, a series from humans down to amoebae with only the slightest differences in natural capacities between each successive species), therefore the problems of arbitrariness and inequality will apply equally to the "natural capacities" view. In other words, there is a continuum not only of developed but of "natural" capacities, and so the "natural capacities" view will inevitably face these problems as well.