Garnier was a Bonapartist senator. Bonapartism is based upon the petit-bourgeois strata in society. It was no wonder then, Marx says, that Garnier should see the assorted components of this strata as fulfilling a useful productive role.
“In fact, no class provides a more worthless section of recruits for the petty bourgeoisie. Garnier does not understand how Smith, “a man who has observed things with such sagacity”, does not value more highly “this intermediary, placed close to the rich, in order to gather up the scraps of revenue which the latter so thoughtlessly dissipates” (l.c., pp. 82, 183). He himself says in this sentence that he merely “gathers up” the scraps of “revenue”. But of what does this revenue consist? Of the unpaid labour of the productive labourer.” (p 201)
This idea that it is consumption that fulfils a productive function, by creating demand for the commodities that capital produces, was also found in Malthus, as the advocate of the landlord class. But, it is also found amongst the proponents of underconsumptionist theories of capitalist crisis too.
Keynes suggested that people could be put to work digging holes, and then paid to fill them in again, so as to provide them with wages to spend. Proponents of “The Permanent Arms Economy Thesis” make the similar claim that capitalism is led to spend vast sums, unproductively, in arms production, so as to soak up surplus capital, and avoid mass unemployment.
In Garnier's case, part of the explanation for such ideas stems from his own relapse into Physiocratic beliefs. He declares only agricultural labour to be productive because, ““it creates another new value, a value which did not exist in society, even as an equivalent, at the moment when this labour began to be performed; and it is this value which provides a rent to the owner of the land” (l.c., p. 184).” (p 201-2)
But, as Marx points out, if this Physiocratic concept is stripped of its limitations, based upon the conception of value as use value, then the conclusion that Garnier should have reached, and that Smith did reach, in his first definition, is that productive labour is that which exchanges with capital.
On the definition that Garnier has set out, productive labour is that which produces a surplus value, an additional value that did not exist, but that only exists because that labour has created a greater sum of value than it itself represents. A given value of labour-power, determined by the labour-time required for its production, creates a larger quantity of value, as a consequence of the expenditure of that labour-power in production. The difference between the value of that labour-power, bought by capital, and the value created by that labour-power, in the service of capital, is precisely the surplus value, ““a new value, a value which did not exist in society, even as an equivalent, at the moment when this labour began to be performed”.” (p 202)