Classical conceptions defined beauty in terms of the relation between the beautiful object as a whole and its parts: proportionate and harmonious. The outstanding qualities of the sublime were vastness and obscurity: grandiose and terrifying. The characteristics of the picturesque were roughness and sudden variation joined to irregularity of form.

  In 1782 enlightenment and rationalist ideas about aesthetics were being challenged by looking at the experiences of beauty and sublimity as non-rational. Aesthetic experience was not just a rational decision. Influential for the development of this position was John Locke’s distinction between primary qualities, which the object has independent of the observer, and secondary qualities which constitute powers in the object to produce certain ideas in the observer.