Lost Highway Times...Paths in Oblivion

Why you should read it: during the time frame that Thompson, author of "The Making of the English Working Class", chronicles the shift from Enlightenment Liberalism to Socialism was happening, and the Romantics were at the forefront, the philosophical forefront, of this transition. It was also several decades before Marx. There's also the switch in labor, or actually the reformulation of the labor movement and its push for social equality but that's not what this volume deals with.

If you want to see why socialism came into being, the Romantic period of the early to mid 19h century, with the traditional cut off point being 1848, is a good one to look at.