 As is well known, while adhering to the basic Benthamic analysis of motives, in Utilitarianism (1861) J. S. Mill introduced the concept of“higher pleasures”, by which he meant aesthetic and spiritual gratification and the pleasures of the intellect, and claimed these were intrinsically more desirable than other pleasures. This tended to undermine the aggregative dimension of the theory laid down by Bentham, since the depth of feeling associated with such pleasures resist quantification. Recent commentators, however, have questioned whether the distance between Bentham and Mill is as large as commonly supposed, arguing for example that “intensity” and “purity” are qualities of pains and pleasures that, in principle, are still subject to measurement, at least when comparing alternative actions on the same index (Warke 2000; Rosen 2003, Ch. 10).