That a state of rest and inaction, however it may flatter our indolence, should be productive of many inconveniences; 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...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...labour is not only requisite to preserve the coarser organs in a state fit for their functions, but it is equally necessary to these finer and more delicate organs, on which, and by which, the imagination, and perhaps the other mental powers act...to have them in proper order, they must be shaken and worked to a proper degree.