What is most striking from Wheen's portrayal is Marx's gargantuan intellectual appetite. From his
earliest writings there appears no subject that was not of interest to him
—
history, anci
ent and modern
philosophy, economics, art, literature, geology, natural science, ethnology, and mathematics. This
surely makes any effort to sum up his contribution far from easy. So formidable was Marx's output
that although he published only a handful of
books in his lifetime (including one volume of his
planned multivolume magnum opus Das Kapital), his collected works come to more than 100
volumes, and the work of transcribing and publishing all his writings remains to be completed even
today.