He now desired that the "Treatise of Human Nature" should be treated as a work blotted out of literature, and that the "Inquiry" should be substituted in its place. In the subsequent editions of the latter work, he complained that this had not been complied with; that the world still looked at those forbidden volumes of which he had dictated the suppression. "Henceforth," he says, "the author desires that the following pieces may alone be regarded as containing his philosophical principles and sentiments;" and he became eloquent on the uncandidness of bringing before the world as the sentiments of any author, a work written almost in boyhood, and printed at the threshold of manhood. But it was all in vain: he had to learn that the world takes possession of all that has passed through the gates of the printing press, and that neither the command of despotic authority, nor the solicitations of repentant authorship can reclaim it, if it be matter of sterling value. The bold and original speculations of the "Treatise" have been, and to all appearance ever will be, part of the intellectual property of man; great theories have been built upon them, which must be thrown down before we can raze the foundation. That he repented of having published the work, and desired to retract its extreme doctrines, is part of the mental biography of Hume; but it is impossible, at his command, to detach this book from general literature, or to read it without remembering who was its author. But, indeed, there were pretty cogent reasons why the philosophical world, and Hume's opponents in particular, should not lose sight of his early work. In the Inquiry, he did not revoke the fundamental doctrines of his first work. The elements of all thought and knowledge he still found to be in impressions and ideas. But he did not on this occasion carry out his principles with the same reckless hardihood that had distinguished the Treatise; and thus he neither on the one side gave so distinct and striking a view of his system, nor on the other afforded so strong a hold to his adversaries. This hold they were resolved not to lose; and therefore they retained the original bond, and would not accept of the offered substitute. Of those views which are more fully developed in the Inquiry than in the early work, one of the most important is the attempt to establish the doctrine of necessity, and to refute that of free will in relation to the springs of human action. To those who adopted the vulgar notion of Hume's theory of cause and effect, that it left the phenomena of nature without a ruling principle, the attempt to show that the human mind was bound by necessary laws appeared to be a startling inconsistency--a sort of reversal of the poet's idea, And binding nature fast in fate, Left free the human will. It appeared to remove the chains of necessity from inanimate nature, and rivet them on the will.