Providence has so ordered it, that a state of rest and inaction, however it may flatter our indolence, should be productive of many inconveniencies; that it should generate such disorders, as may force us to have recourse to some labour, as a thing absolutely requisite to make us pass our lives with tolerable satisfaction; for the nature of rest is to suffer all the parts of our bodies to fall into a relaxation, that not only disables the members from performing their functions, but takes away the vigorous tone of fibre which is requisite for carrying on the natural and necessary secretions. At the same time, that in this languid inactive state, the nerves are more liable to the most horrid convulsions, than when they are sufficiently braced and strengthened. Melancholy, dejection, despair, and often self-murder, is the consequence of the gloomy view we take of things in this relaxed state of body. The best remedy for all these evils is exercise or labour; and labour is a surmounting of difficulties, an exertion of the contracting power of the muscles; and as such resembles pain, which consists in tension or contraction, in every thing but degree.

— A philosophical enquiry into the origin of our ideas of the sublime and beautiful by Edmund Burke (The World's classics) (Page 164)