INTRODUCTION The explanation of monetary phenomena and the classical theory. MonNETARY systems give rise in their operation to phenomena which from their first appearance have en- gaged the attention of thinkers as also of economists since such have existed. The explanation of these phenomena appears to rest upon a few simple premises which need only to be judiciously combined in order to explain any particular case. Money, it is commonly said in virtue of a doctrine now classical, 1s essentially a commodity. As such it is subject to the action of supply and demand, and its value varies in- versely as its amount. This proposition is known as the Quantity Theory and seems to afford a key to almost all monetary problems. Thus, taking in the first place those problems which arise out of the concurrent use of two metals, gold and silver, we are assured that if one of these metals stands at a premium with regard to the other, this is obviously due to the latter being produced in excess. Even Gresham's law, although it is the result of a piece of direct observation, namely, that bad money drives out good, can be linked up with this Theory. It is no doubt true that when money is at a premium it is exported be- cause it is preferable for the purpose of making payments to foreign countries where it 1s admitted for the sake of its “intrinsic value” ; or again, that it disappears because it is hoarded by cautious people who are confident that it will maintain its value, and lay it by in the hope of better times. In any case, it disappears. But what 1s there behind this YJ