The most general and most palpable phenomenon in commercial crises is the sudden, general decline of prices following a prolonged general rise. The general decline of prices of commodities may be expressed as a rise in the relative value of money with respect to all commodities, and the general rise of prices as a decline of the relative value of money. In either expression the phenomenon is described but not explained. Whether I put the question thus: explain the general periodic rise of prices followed by a general decline of the same, or formulate the same problem by saying: explain the periodic decline and rise of the relative value of money with respect to commodities; the different wording leaves the problem as little changed as would its translation from German into English. Ricardo’s theory of money was exceedingly convenient, because it lends a tautology the semblance of a statement of causal connection. Whence comes the periodic general fall of prices? From the periodic rise of the relative value of money. Whence the general periodic rise of prices? From the periodic decline of the relative value of money. It might have been stated with equal truth that the periodic rise and fall of prices is due to their periodic rise and fall. The problem itself is stated under the assumption that the intrinsic value of money, i. e., its value as determined by the cost of production of precious metals remains _unchanged_. If it is more than a tautology then it is based on a misconception of the most elementary principles. If the exchange value of A measured in terms of B, declines, we know that this may be caused by a decline of the value of A as much as by a rise of the value of B; the same being true of the case of a rise of the exchange value of A measured in terms of B. The tautology once admitted as a statement of cause, the rest follows easily. A rise of prices of commodities is caused by a decline of the value of money and a decline of the value of money is caused, as we know from Ricardo, by a redundant currency, i. e., by a rise of the volume of currency over the level determined by its own intrinsic value and the intrinsic value of the commodities. In the same manner, the general decline of prices of commodities is explained by the rise of the value of money above its intrinsic value in consequence of an inadequate currency. Thus, prices rise and fall periodically, because there is periodically too much or too little money in circulation. Should a rise of prices happen to coincide with a contracted currency, and a fall of prices with an expanded one, it may be asserted in spite of those facts that in consequence of a contraction or expansion of the volume of commodities in the market, which can not be proven statistically, the quantity of money in circulation has, although not absolutely, yet relatively increased or declined. We have seen that according to Ricardo these universal