Sentimentalism is a practice of being sentimental, and thus tending toward basing actions and reactions upon emotions and feelings, in preference to reason. As a literary mode, sentimentalism has been a recurring aspect of world literature. Sentimentalism includes a variety of aspects in literature, such as sentimental poetry, the sentimental novel, and the German sentimentalist music movement, Empfindsamkeit. European literary sentimentalism arose during the Age of Enlightenment, partly as a response to sentimentalism in philosophy. In eighteenth-century England, the sentimental novel was a major literary genre. Its philosophical basis primarily came from Anthony Ashley Cooper, 3rd Earl of Shaftesbury, a pupil of John Locke. Sentimentalism in philosophy and sentimentalism in literature are sometimes hard to distinguish. As the philosophical arguments developed, the literature soon tried to emulate by putting the philosophical into practice through narration and characters. As a result, it is common to observe both philosophical and literary movements simultaneously. Philosophically, sentimentalism was often contrasted to rationalism. While eighteenth-century rationalism corresponded itself with the development of the analytic mind as the basis for acquiring truth, sentimentalism hinged upon an intrinsic human capacity to feel and how this leads to truth. For the sentimentalist this capacity was most important in morality (moral sense theory). Sentimentalists contended that where the rationalists believed morality was founded upon analytic principles (e.g. Immanuel Kant's "Categorical Imperative"), these principles could not be adequately founded in the empirical nature of humans—such as observing a sad image or expressing a strong emotion physically. Therefore, one could not obtain a sound moral theory. However, by developing the moral sensibility and fine tuning the capacity to feel, a person could access a sound moral theory by building from an intrinsic human nature, which each person possessed.