Professor Marshall summarizes the tendency in the following words—­“We are thus led to a general rule, the action of which is more prominent in some branches of manufacture than others, but which applies to all.  It is, that any manufacturing operation that can be reduced to uniformity, so that the same thing has to be done over and over again in the same way, is sure to be taken over sooner or later by machinery.  There may be delays and difficulties; but if the work to be done by it is on a sufficient scale, money and inventive power will be spent without stint on the task till it is achieved.  There still remains the responsibility for seeing that the machinery is in good order and working smoothly; but even this task is often made light of by the introduction of an automatic movement which brings the machine to a stop the instant anything goes wrong."[16]

Since the economy of production constantly induces machinery to take over all work capable of being reduced to routine, it would seem to follow by a logical necessity that the work left for the human worker was that which was less capable of being subjected to close uniformity; that is work requiring discretion and intelligence to be applied to each separate action.  Although the process described by Professor Marshall assigns a constantly diminishing proportion of each productive work to the effort of man, of that portion which remains for him to do a constantly increasing proportion will be work of judgment and specific calculation applied to particular cases.  And this is the conclusion which Professor Marshall himself asserts—­

“Since machinery does not encroach much upon that manual work which requires judgment, while the management of machinery does require judgment, there is a much greater demand now than formerly for intelligence and resource.  Those qualities which enable men to decide rightly and quickly in new and difficult cases, are the common property of the better class of workmen in almost every trade, and a person who has acquired them in one trade can easily transfer them to another.”

If this is true, it signifies that the formal specialization of the worker, which comes from his attendance on a more and more specialized piece of machinery, does not really narrow and degrade his industrial life, but supplies a certain education of the judgment and intelligence which has a general value that more than compensates the apparent specialization of manual functions.  The very fact that the worker’s services are still required is a proof that his work is less automatic (i.e. more intelligent) than that of the most delicate machinery in use; and since the work which requires less intelligence is continually being taken over by machinery, the work which remains would seem to require a constantly higher average of intelligence.  It is, of course, true that there are certain kinds of work which can never be done by machinery, because they require a little care