"If he merely puts his savings in a stocking, like the proverbial French peasant, it is obvious that they do not give employment."

What is "obvious" to Bertrand Russell is bad economics.

When the peasant puts his money in a stocking, he causes a slight deflation, so prices decrease, which increases the value of everyone else's money. So everyone else effectively has more to spend, if they want to.

However, everyone else would be prudent to assume that the peasant will eventually spend his money, which will correspondingly cause prices to rise again.

It might seem that an earlier gain is offset by a later loss.

But, those who benefit from the slight deflation can choose to invest the increased value of their monetary holdings into industry. At a later time, when the peasant decides to spend his money, the products of that industry will be ready for purchase.

Thus, with nothing more than surplus cash and a stocking, the peasant has driven investment in industry, productive employment, and long-term growth in the wealth of society, the benefits of which he has foregone since he chose not to seek a return of interest on his savings.