During your visit in London next week I hope you will stay with us in
Brook Street, and I am commissioned by Mrs. Ricardo to add her
solicitations to mine to induce Mrs. Malthus to accompany you.
Lord King[180], Mr. Whishaw and you have done me a great deal of honour
in making my work[181] the subject of your discussions, but I confess it
fills me with astonishment to find that you think, and from what you say
they appear to agree with you, that the measure of value is not what I
have represented it to be; but that _natural price_, as well as _market
price_, is determined by the demand and supply,--the only difference
being that the former is governed by the average and permanent demand
and supply, the latter by the accidental and temporary. In saying this
do you mean to deny that facility of production will lower natural
price, and difficulty of production raise it? Will not these effects be
produced after a very short interval, although the absolute demand and
supply, or the proportion of one to the other, should remain permanently
the same? At any rate then demand and supply are not the sole regulators
of price. I should be glad to understand what Lord King and you mean by
supply and demand. However abundant the demand it can never permanently
raise the price of a commodity above the expense of its production,
including in that expense the profits of the producers. It seems natural
therefore to seek for the cause of the variation of permanent price in
the expenses of production. Diminish these and the commodity must
finally fall, increase them and it must as certainly rise. What has this
to do with demand? I may be so foolishly partial to my own doctrine that
I may be blind to its absurdity. I know the strong disposition of every
man to deceive himself in his eagerness to prove a favourite theory, yet
I cannot help viewing this question as a truth which admits of
demonstration and I am full of wonder that it should admit of a doubt.
If indeed this fundamental doctrine of mine were proved false I admit
that my whole theory falls with it, but I should not on that account be
satisfied with the measure of value which you would substitute in its
place.