The following series of Letters appeared, with two exceptions, in The Daily News, (1862, 1863). My best thanks are due to the Editor of that journal for the readiness with which he admitted them into his columns. He always lends a generous protection to independent thought, the salt without which all our liberties would lose their savour.

I did not intend, when the letters were written, to reprint them in that form; but when I tried to put the matter of them into a more regular shape, I found that the discussion which ran through the series had followed the main lines of thought, and that in attempting to be more methodical I only became less clear.

Most of the letters, however, have been revised; some have been amplified, partly by taking up into them defences of their arguments which originally appeared in short supplementary letters; to some, more appropriate titles have been given. The order of subjects has been substituted for the order of dates; but the dates have been retained, because in some cases they point to the occasions on which the letters were written.

The first of the series, with the article of The Times appended, stands as it was. The Times' article is most valuable, because it gives the reader, on the best possible authority, the dominant view of the question, and the arguments by which that view is supported.