there was once a millionaire who bought an infinite number of pairs of shoes and, whenever he bought a pair of shoes, he also bought a pair of socks. We can make a selection choosing one out of each pair of shoes, because we can choose always the right shoe or always the left shoe. Thus, so far as the shoes are concerned, selections exist. But, as regards the socks, where there is no distinction of right and left, we cannot use this rule of selection.

pp. 93-93 - My Philosophical Development (1959)