Desire to awaken the people to the danger that lay in the growth of the national sin made him begin to lecture in 1844. Invitations flowed in freely; and he said, after he had broken down under the joint burden of overwork and of exposure in travelling: "Since 1848, I have lectured eighty or a hundred times each year, in every Northern State east of the Mississippi,--once also in a slave State and on slavery itself." This was his favourite subject, but he never missed an opportunity of encouraging intellectual independence; and he found he could say what he pleased. The total number of hearers exceeded half a million; among them were the most influential men in the North; and he never failed to make himself understood. No one else did so much to develop that love of the people for Union and Liberty which secured emancipation. His works have no such brilliancy as Emerson's; but they burned at the time of need with a much more warm and steady light. No words did more to melt the chains of millions of slaves. No excess of individualism made him shrink back, like Emerson, from joining the abolitionists; or discredit them, as Thoreau did, by publicly renouncing his allegiance to Massachusetts in 1854, when that State stood foremost on the side of freedom. The account of a solitary life in the woods, which Thoreau published that year, has done much to encourage independence of public opinion; and Americans of that generation needed sadly to be told that they took too little amusement, especially out of doors, and made too great haste to get rich. Their history, however, like that of the Swiss, Scotch, and ancient Athenians, proves that it is the industrious, enterprising, money-making nations that are best fitted for maintaining free institutions. As for individual independence of thought and action, the average man will enjoy much more of it, while he keeps himself in comfortable circumstances by regular but not excessive work, than he could if he were to follow the advice of an author who prided himself on not working more than "about six weeks in a year," and on enduring privations which apparently shortened his days. Thoreau's self-denial was heroic; but he sometimes failed to see the right of his neighbours to indulge more expensive tastes than his own. The necessary conditions of health and comfort for different individuals vary much more than he realised. Many a would-be reformer still complains of the "luxury" of people who find physical rest or mental culture in innocent ways, not particularly to his own fancy. Such censures are really intolerant. They are survivals of that meddlesome disposition which has sadly restricted freedom of trade, amusement, and worship.