My dear Sir,
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.
I am sorry that you have determined not to publish this spring.
I have not seen Torrens, and do not know what his intentions are respecting the work which he promised to give to the public.
Sir James Mackintosh is indeed a great acquisition in more respects than one to your College[182]. It must be particularly agre[e]able to you.
I thank you for your congratulations on the honor [which] has been conferred on me by the appointment [to] the office of Sheriff[183], an honour which I could well have dispensed with. Under all circumstances I think it best not to offer an objection to it.
I wish you were of our party to-day. Mr. Whishaw, Mr. Smyth, Mr. Mallet, Mr. Sharp and Mr. Warburton dine with me.
I am glad that you have heard Mill's book[184] favourably spoken of. I hope it may be as well thought of by others as it is by me.
Very truly yours,
David Ricardo.