lever, the wheel, the inclined plane; professional force is manifest in intellectual ingenuity, literature, art, science, which are the machines of human progress.
How many of all our joys and sorrows, our loves and hates, our good and evil actions, spring from physical causes only? Even material substances display moods and affections, as when heated, electrified, decomposed, or set in motion; the sea at rest presents a different mood from the sea raging. Jean-Jacques Rousseau's idea that the soul might be governed for its good by material things working through the media of the senses, is not so extravagant after all. "The gospel according to Jean-Jacques," as Carlyle puts it, runs as follows on this point—and, indeed, the great Genevan evangelist at one time intended to devote a book to the subject under the title of La Morale Sensitive:—"The striking and numerous observations that I had collected were beyond all dispute; and, in their physical origin, they appeared to me proper for furnishing an exterior regimen, which, varied according to circumstances, should be able to place or maintain the soul in the state most favorable to virtue. How many wanderings one might save the reason, how many vices might be hindered birth, if one could but force the animal economy to favor the moral order that it troubles so often. Climates, seasons, sounds, colors, darkness, light, the elements, food, noise, silence, movement, repose, all act on our bodily frame, and, by consequence, on our soul; all offer us a thousand firm holds to govern, in their origin, those sentiments by which we allow ourselves to be dominated."
In contemplating the numerous activities by which we are surrounded, again and again we are called upon to wonder at the marvellous regularity which characterizes all their movements. So regular are these movements, so sure are certain conditions to accompany certain results, that in physics, in chemistry, in physiology, and even in society, facts are collected and classified, and from them laws are discovered as fixed
