The greater part of this was published in 1927; now, twenty years later, with fear of communism rampant, this revision and reissue is sound publishing. The original text contained 13 chapters; those chapters have been brought up to date with a few minor changes and footnotes; nine chapters have been added, bringing the historical pattern into line, indicating post war trends, suggesting alternatives we must face ahead. There's additional source material in the appendix -- official instructions for communist factions, the Constitution of the IIIrd International, Nazi-Communist Parallels, etc. There's a sharp difference in style, tempo, as well as content in the 1927 material and the 1946 material. Where the first is specifically detailed in tracing the development, expansion, splits, and disintegration of successive communist infiltration efforts here -- all handled so dispassionately as to seem dry and dull reading; the final chapters are angry, more dramatic, more personal. One gets a sense of history in the making; of a determination to put over the realization that, while their numbers are small, their processes are all-pervading,- the body politic, industry, commerce, the unions, the arts, the press, and so on. At times, sweeping generalizations weaken the argument, as for instance ""the united front developed into the United Nations and the Communists still are strong supporters...""- the implication being that this too was created as their tool. The ""Innocents' Clubs"", the ""transmission belts"" media of fellow travellers; the capturing of the Socialists, of the CIO, of the American Labor Party- these are sure to bring controversial issues to the fore, for the authors seem to feel there is no possibility of error, even in degree. In the chapter devoted to the choice before us, they indicate that we are launched on the road of a mixed economy within the range of democratic policy and administration, and that- so long as we know where the communists are boring from within -- we can travel this road wisely, and avoid the peril of succumbing to revolution and totalitarianism, whither they would lead.