The Hi, I'm Peter Adamson and you're listening to the History of Philosophy Podcast, brought to you with the support of the philosophy department at

Kings College London and the LMU in Munich. Online at www. History of Philosophy.net.

Today's episode, On the Money, Medieval Economic Theory. Suppose you are a

medieval merchant traveling with a wagon load of grain to a town where grain is in short supply.

Given the circumstances, you know that you'll be able to sell your goods for a high price,

perhaps double or triple, the usual going rate.

You also happen to know that only one day's travel behind

you, another much larger shipment of grain is headed towards the same city. Do you have the obligation

to reveal this to your customers for going your advantage and selling at the normal price?

Your answer might depend on whether you had read Thomas Aquinas.

In his Sumatologia, he asks what a merchant in this situation ought to do.

His answer is that the bounds of justice do not require divulging information that would reduce the price, even though it would be particularly admirable, were the merchant honest enough to do so.

A similar example is considered by Henry of Ghent, who allows someone to buy a horse and then sell it in the same city at a higher price only one hour later, if in the intervening time all other horses on the market have been taken away from the city on ships.

Such cases raise problems that were central in medieval thinking about economics.

It's not a subject we have discussed very much here on the podcast, even though a not dissimilar example came up in the very first episode, where we heard of the pre-Socratic philosopher Thales buying up all the olive oil presses to reap a windfall from a

bumper crop of olives he had predicted.

We know that story because we are told it in Aristotle's politics in the midst of a discussion of money-making to illustrate the concept of a monopoly.

It's a text that left the medieval's with complicated feelings on the subject of money and money making.

While Aristotle recognizes what he calls a natural art of dealing with money, which needs

to be practiced by householders and politicians, he is disdainful of unnatural pursuit

of boundless wealth and of those who see money as an end in itself.

Rather, as Aristotle had already explained in the ethics, money is really an instrument of exchange,

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