"The cost of a thing," says he, "is _the amount of what I will call life_ which is required to be exchanged for it, immediately or in the long run." I have been accustomed to put it to myself, perhaps more clearly, that the price we have to pay for money is paid in liberty. Between these two ways of it, at least, the reader will probably not fail to find a third definition of his own; and it follows, on one or other, that a man may pay too dearly for his livelihood, by giving, in Thoreau's terms, his whole life for it, or, in mine, bartering for it the whole of his available liberty, and becoming a slave till death. There are two questions to be considered--the quality of what we buy, and the price we have to pay for it. Do you want a thousand a year, a two thousand a year, or a ten thousand a year livelihood? and can you afford the one you want? It is a matter of taste; it is not in the least degree a question of duty, though commonly supposed so. But there is no authority for that view anywhere. It is nowhere in the Bible. It is true that we might do a vast amount of good if we were wealthy, but it is also highly improbable; not many do; and the art of growing rich is not only quite distinct from that of doing good, but the practice of the one does not at all train a man for practising the other. "Money might be of great service to me," writes Thoreau; "but the difficulty now is that I do not improve my opportunities, and therefore I am not prepared to have my opportunities increased." It is a mere illusion that, above a certain income, the personal desires will be satisfied and leave a wider margin for the generous impulse. It is as difficult to be generous, or anything else except perhaps a member of Parliament, on thirty thousand as on two hundred a year. Now Thoreau's tastes were well defined. He loved to be free, to be master of his times and seasons, to indulge the mind rather than the body; he preferred long rambles to rich dinners, his own reflections to the consideration of society, and an easy, calm, unfettered, active life among green trees to dull toiling at the counter of a bank. And such being his inclination he determined to gratify it. A poor man must save off something; he determined to save off his livelihood. "When a man has attained those things which are necessary to life," he writes, "there is another alternative than to obtain the superfluities; _he may adventure on life now_, his vacation from humbler toil having commenced." Thoreau would get shelter, some kind of covering for his body, and necessary daily bread; even these he should get as cheaply as possible; and then, his vacation from humbler toil having commenced, devote himself to Oriental philosophers, the study of nature, and the work of self-improvement.