“Who would plough or sow if he disbelieved in the fixity of the future?  Who would throw water on a blazing house if the action of water upon fire were uncertain?  Men will only do their utmost when they feel certain that the future will discover itself against them if their utmost has not been done.  The feeling of such a certainty is a constituent part of the sum of the forces at work upon them, and will act most powerfully on the best and most moral men.  Those who are most firmly persuaded that the future is immutably bound up with the present in which their work is lying, will best husband their present, and till it with the greatest care.  The future must be a lottery to those who think that the same combinations can sometimes precede one set of results, and sometimes another.  If their belief is sincere they will speculate instead of working:  these ought to be the immoral men; the others have the strongest spur to exertion and morality, if their belief is a living one.

“The bearing of all this upon the machines is not immediately apparent, but will become so presently.  In the meantime I must deal with friends who tell me that, though the future is fixed as regards inorganic matter, and in some respects with regard to man, yet that there are many ways in which it cannot be considered as fixed.  Thus, they say that fire applied to dry shavings, and well fed with oxygen gas, will always produce a blaze, but that a coward brought into contact with a terrifying object will not always result in a man running away.  Nevertheless, if there be two cowards perfectly similar in every respect, and if they be subjected in a perfectly similar way to two terrifying agents, which are themselves perfectly similar, there are few who will not expect a perfect similarity in the running away, even though a thousand years intervene between the original combination and its being repeated.

“The apparently greater regularity in the results of chemical than of human combinations arises from our inability to perceive the subtle differences in human combinations—­combinations which are never identically repeated.  Fire we know, and shavings we know, but no two men ever were or ever will be exactly alike; and the smallest difference may change the whole conditions of the problem.  Our registry of results must be infinite before we could arrive at a full forecast of future combinations; the wonder is that there is as much certainty concerning human action as there is; and assuredly the older we grow the more certain we feel as to what such and such a kind of person will do in given circumstances; but this could never be the case unless human conduct were under the influence of laws, with the working of which we become more and more familiar through experience.

“If the above is sound, it follows that the regularity with which machinery acts is no proof of the absence of vitality, or at least of germs which may be developed into a new phase of life.  At first sight it would indeed appear that a vapour-engine cannot help going when set upon a line of rails with the steam up and the machinery in full play; whereas the man whose business it is to drive it can help doing so at any moment that he pleases; so that the first has no spontaneity, and is not possessed of any sort of free will, while the second has and is.