To render the exchange productive the value of the whole amount of service must be balanced by the value of the product.

If this condition is not complied with, the exchange is unequal; the producer gives more than he receives." Now, value being necessarily based upon utility, it follows that every useless product is necessarily valueless,--that it cannot be exchanged; and, consequently, that it cannot be given in payment for productive services.
Then, though production may equal consumption, it never can exceed it; for there is no real production save where there is a production of utility, and there is no utility save where there is a possibility of consumption.

Thus, so much of every product as is rendered by excessive abundance inconsumable, becomes useless, valueless, unexchangeable,--consequently, unfit to be given in payment for any thing whatever, and is no longer a product.
Consumption, on the other hand, to be legitimate,--to be true consumption,--must be reproductive of utility; for, if it is unproductive, the products which it destroys are cancelled values--things produced at a pure loss; a state of things which causes products to depreciate in value.

Man has the power to destroy, but he consumes only that which he reproduces.

Under a right system of economy, there is then an equation between production and consumption.
These points established, let us suppose a community of one thousand families, enclosed in a territory of a given circumference, and deprived of foreign intercourse.