The modern left was crippled at the start by the moment in which it was born, and thrived: the onset of the post-Romantic, post-Enlightenment period of the growth of scientism. The strange world of Hegel, and the reaction against it was part of the whole rationale of Marx and Engels but in retrospect one wonders if that was the right keynote.
The net result was a limited materialism, an egregious anti-idealism (who cares, actually, idealism is not an issue of social justice, once we move past its false exemplars), a confusion over consciousness and a view of history that seems brittle now.
The left now confronts the immense riddle of world religion and the backwash of the so-called ‘new age’ movement which nonetheless leaves behind the traces of the mysterious religions of antiquity. The left is notably unequipped with its marxist reductionist to make any sense of the past of man. The result no longer appeals to modern man in the period we now live in which the collision of idealism and materialism seems quaint and too entangled in the now irrelevant anti-Hegel reaction.
A reconstructive understanding of antiquity here is beyond the means of the modern left and that situation will need to change on the way to a socialist future. The problem is not so hard to solve but can the narrow muddle of the marxists ever manage here?