Interesting work, back in print. The political perspective of Kantianism tends to reflect the legacy of classical liberalism(e.g. the Kantian Hayek), revolutionary for its time, but the inherent dialectic of the Kantian ethics proceeds to its universality as a social conundrum, which produced a most significant commentary on the socialist idea in the period of the 'back to Kant' movement at the end of the nineteenth century. This fascinating work reviews the logic and tells the history of this period and initiative, and its outcome in the era of Social Democracy leading up to the period of the Weimar collapse. These Kantians, e.g. Cohen, Vorlander, and the Marburg school,are of great historical interest still, as we forget that many of the critiques of the original Marxism now brandished by conservatives found their source in these Kantians. If only the history had been different! This corner of history was eliminated in the later stages of madness (the twenties, Eisner was assinated by early Nazis). The book is filled with all sorts of curious discussions, e.g. a critique of Hegelian teleology, Rawlsian implications, etc. It should be of interest as it will keep both left and right honest, on their, your, toes.
See also Willey's Back to Kant