ECONOMIC PRINCIPLES
work of their production. Until the goods have, not merely
the form, but the position, desired, their production is not
complete. Brick and stone, iron and wood, need to be placed
in position to produce a building, and the labour of conveying
 them from the place of manufacture to the site of the
building is not less essential, to their finding their due places
in the building, than the labour of placing them in position
as parts of the building itself. In both cases it is a moving
of material to a place where it can serve a useful purpose.
Those who are engaged in the designing of the structure,
and in controlling the operations needed for its effective
construction, are also, obviously, productive, in so far as the
result could not be attained without their co-operation. The
aid in effectively carrying out such business operations,
which the designers, and those engaged in the transportation
and commercial operations needed for its completion, render,
is not the only indirect aid to the efficient performance of
the manual labour of construction. The maintenance of law
and order, of freedom from internal disturbance or foreign
aggression, is also an important contribution to all classes of
labour and enterprise. Administrative officials, and military
officers and men, thus contribute their quota to the industry
and commerce of the community. The degree in which the
members of the teaching profession fall within the same
category, though not equal for all, is sufficiently clear in
reference to them as a body to need no special comment,
In reference to those who render direct personal services,
including public singers, actors, and musicians, we are concerned
 chiefly with the production of non-material satisfactions.
 There seems no reason for classifying the writer of
romances, whose work is presented in the material form of a
book, as productive, and the musician, who affords a pleasure
at least as real when playing a musical instrument, as
unproductive, though the latter pleasure cannot be repeated
without the intervention of the musician, while the book can
be re-read as often as one desires. If, for any purpose, the
contrast between the producers of wealth in material or in
durable forms, and those whose productions are either nonmaterial
 or not durable, be required, it can be made without