Page:Popular Science Monthly Volume 3.djvu/433

Rh around Havre and Lyons, but has not realized the hopes of its promoters, its dispatches being often illegible.

Instead of a series of parallel lines, the styles may be made to trace the successive convolutions of a fine helix, the two sheets being bent round two cylinders, which revolve in equal times, and also advance longitudinally.



N the foregoing eight chapters we have contemplated, under their several heads, those "Difficulties of the Social Science" which the chapter bearing that title indicated in a general way. After thus warning the student against the errors he is liable to fall into, partly because of the nature of the phenomena themselves and the conditions they are presented under, and partly because of his own nature as observer of them—which by both its original and its acquired characters causes twists of perception and judgment—it now remains to say something about the needful preliminary studies. I do not refer to studies furnishing the requisite data, but I refer to studies giving the requisite discipline. Right thinking in any matter depends very much on the habit of thought; and the habit of thought, partly natural, depends in part on the artificial influences to which the mind has been subjected.

As certainly as each person has peculiarities of bodily action that distinguish him from his fellows, so certainly has he peculiarities of mental action that give a character to his conceptions. There are tricks of thought as well as tricks of muscular movement. There are acquired mental aptitudes for seeing things under particular aspects, as there are acquired bodily aptitudes for going through evolutions after particular ways. And there are intellectual perversities produced by certain modes of treating the mind, as there are incurable awkwardnesses due to certain physical activities daily repeated.

A truth ever to be remembered is, that each kind of mental discipline, besides its direct effects on the faculties brought into play, has its indirect effects on the faculties left out of play; and when special benefit is gained by extreme special discipline, there is inevitably more or less general mischief entailed on the rest of the mind by the consequent want of discipline. That antagonism between body and brain which we see in those who, pushing brain-activity to an extreme, enfeeble their bodies, and those who, pushing bodily activity to an extreme, make their brains inert, is an antagonism which holds between 