production in the largest, or in the most restricted sense in which they
have ever yet been employed, nobody will dispute that roads, bridges,
and canals, contribute in an eminent degree, and in a very direct
manner, to the increase of production and wealth. The labour and
pecuniary resources employed in their construction would, according to
the above theory, be considered productive, if every occupier of land
were compelled by law to construct so much of the road, or canal, as
passes through his own farm. If, instead of this, the government makes
the road, and throws it open to the public toll-free, the labour and
expenditure would be, on the above system, clearly unproductive. But if
the government, or an association of individuals, made the road, and
imposed a toll to defray the expense, we do not see how these writers
could refuse to the outlay the title of productive expenditure. It would
follow, that the very same labour and expense, if given gratuitously,
must be called unproductive, which, if a charge had been made for it,
would have been called productive.

When these consequences of the purely arbitrary classification to which
we allude have been pointed out and complained of, the only answer which
we have ever seen made to the objection is, that the line of demarcation
must be drawn somewhere, and that in every classification there are
intermediate cases, which might have been included, with almost equal
propriety, either in the one class or in the other.

This answer appears to us to indicate the want of a sufficiently
accurate and discriminating perception, what is the kind of inaccuracy
which generally cannot be avoided in a classification, and what is that
other kind of inaccuracy, from which it always may be, and should be,
exempt.