Bodily Labour is of two Kinds, either that which a Man submits to for his Livelihood, or that which he undergoes for his Pleasure. The latter of them generally changes the Name of Labour for that of Exercise, but differs only from ordinary Labour as it rises from another Motive.
A Country Life abounds in both these kinds of Labour, and for that Reason gives a Man a greater Stock of Health, and consequently a more perfect Enjoyment of himself, than any other Way of Life. I consider the Body as a System of Tubes and Glands, or to use a more Rustick Phrase, a Bundle of Pipes and Strainers, fitted to one another after so wonderful a Manner as to make a proper Engine for the Soul to work with. This Description does not only comprehend the Bowels, Bones, Tendons, Veins, Nerves and Arteries, but every Muscle and every Ligature, which is a Composition of Fibres, that are so many imperceptible Tubes or Pipes interwoven on all sides with invisible Glands or Strainers.
This general Idea of a Human Body, without considering it in its Niceties of Anatomy, lets us see how absolutely necessary Labour is for the right Preservation of it. There must be frequent Motions and Agitations, to mix, digest, and separate the Juices contained in it, as well as to clear and cleanse that Infinitude of Pipes and Strainers of which it is composed, and to give their solid Parts a more firm and lasting Tone. Labour or Exercise ferments the Humours, casts them into their proper Channels, throws off Redundancies, and helps Nature in those secret Distributions, without which the Body cannot subsist in its Vigour, nor the Soul act with Chearfulness.
I might here mention the Effects which this has upon all the Faculties of the Mind, by keeping the Understanding clear, the Imagination untroubled, and refining those Spirits that are necessary for the proper Exertion of our intellectual Faculties, during the present Laws of Union between Soul and Body. It is to a Neglect in this Particular that we must ascribe the Spleen, which is so frequent in Men of studious and sedentary Tempers, as well as the Vapours to which those of the other Sex are so often subject.
not Exercise been absolutely necessary for our Well-being, Nature would not have made the Body so proper for it, by giving such an Activity to the Limbs, and such a Pliancy to every Part as necessarily produce those Compressions, Extentions, Contortions, Dilatations, and all other kinds of
Motions
that are necessary for the Preservation of such a System of Tubes and Glands as has been before mentioned. And that we might not want Inducements to engage us in such an Exercise of the Body as is proper for its Welfare, it is so ordered that nothing valuable can be procured without it. Not to mention Riches and Honour, even Food and Raiment are not to be come at without the Toil of the Hands and Sweat of the Brows. Providence furnishes Materials, but expects that we should work them up our selves. The Earth must be laboured before it gives its Encrease, and when it is forced into its several Products, how many Hands must they pass through before they are fit for Use? Manufactures, Trade, and Agriculture, naturally employ more than nineteen Parts of the Species in twenty; and as for those who are not obliged to Labour, by the Condition in which they are born, they are more miserable than the rest of Mankind, unless they indulge themselves in that voluntary Labour which goes by the Name of Exercise.
My Friend Sir