Just as, to someone who needs gold coins for his expenditure it is all the same whether the material therein, the gold, was dug from the mountains or washed from the sand, provided it is accepted everywhere at the same value, so no one asks, when he is concerned merely with the agreeableness of life, whether presentations of understanding or of sense furnish him with gratification, but only how much and how great is the gratification they furnish him for the longest time.