2.This must be distinguished from nervousness, which, as a rule, indicates a general deficiency of nervous strength; though sometimes it proceeds from nervous irritability or want of balance.A man who has great nervous strength in some directions may have but little in others; the artistic temperament in particular often develops one set of nerves at the expense of others: but it is the weakness of some of the nerves, not the strength of the others, that leads to nervousness.The most perfect artistic natures seem not to have been nervous: Leonardo da Vinci and Shakespeare for example.The term "nervous strength"corresponds in some measure to Heart in Engel's great division of the elements of efficiency into (a) Body, (b) Reason, and (c)Heart (Leib, Verstand und Herz).He classifies activities according to the permutations a, ab, ac, abc, acb, b, ba, bc, bca, bac; c, ca, cb, cab, cba: the order in each case being that of relative importance, and a letter being omitted where the corresponding element plays only a very small part.
In the war of 1870 Berlin University students, who seemed to be weaker than the average soldier, were found to be able to bear fatigue better.
3.A warm climate impairs vigour.It is not altogether hostile to high intellectual and artistic work: but it prevents people from being able to endure very hard exertion of any kind for a long time.More sustained hard work can be done in the cooler half of the temperate zone than anywhere else; and most of all in places such as England and her counterpart New Zealand, where sea-breezes keep the temperature nearly uniform.The summer heats and winter colds of many parts of Europe and America, where the mean temperature is moderate, have the effect of shortening the year for working purposes by about two months.Extreme and sustained cold is found to dull the energies, partly perhaps because it causes people to spend much of their time in close and confined quarters: inhabitants of the Arctic regions are generally incapable of long-continued severe exertion.In England popular opinion has insisted that a "warm Yule tide makes fat churchyard"; but statistics prove beyond question that it has the opposite effect: the average mortality is highest in the coldest quarter of the year, and higher in cold winters than in warm.
4.Race history is a fascinating but disappointing study for the economist: for conquering races generally incorporated the women of the conquered; they often carried with them many slaves of both sexes during their migrations, and slaves were less likely than freemen to be killed in battle or to adopt a monastic life.
In consequence nearly every race had much servile, that is mixed blood in it: and as the share of servile blood was largest in the industrial classes, a race history of industrial habits seems impossible.
5.This was proved by Farr, who eliminated disturbing causes by an instructive statistical device (Vital Statistics, p.139).
6.Freedom and hope increase not only man's willingness but also his power for work; physiologists tell us that a given exertion consumes less of the store of nervous energy if done under the stimulus of pleasure than of pain: and without hope there is no enterprise.Security of person and property are two conditions of this hopefulness and freedom; but security always involves restraints on freedom, and it is one of the most difficult problems of civilization to discover how to obtain the security which is a condition of freedom without too great a sacrifice of freedom itself.Changes of work, of scene, and of personal associations bring new thoughts, call attention to the imperfections of old methods, stimulate a "divine discontent,"and in every way develop creative energy.
7.By converse with others who come from different places, and have different Customs, travellers learn to put on its trial many a habit of thought or action which otherwise they would have always acquiesced in as though it were a law of nature.Moreover, a shifting of places enables the more powerful and original minds to find full scope for their energies and to rise to important positions: whereas those who stay at home are often over much kept in their places.Few men are prophets in their own land;neighbours and relations are generally the last to pardon the faults and to recognize the merits of those who are less docile and more enterprising than those around them.It is doubtless chiefly for this reason that in almost every part of England a disproportionately large share of the best energy and enterprise is to be found among those who were born elsewhere.
But change may be carried to excess; and when population shifts so rapidly, that a man is always shaking himself loose from his reputation, he loses some of the best external aids to the formation of a high moral character.The extreme hopefulness and restlessness of those who wander to new countries lead to much waste of effort in half acquiring technical skill, and half finishing tasks which are speedily abandoned in favour of some new occupation.
