This essay is obstinate in its defense of the classic Marxist formulas and dismissive of any and all criticisms, etc…
Let’s be clear: the issue is socialism and its passage into social realization. The question of Marx’s theories is secondary. Those formulas aim to establish socialism/communism but in reality they have the opposite effect now. And the questions of philosophy can’t be packaged in the way Marxists wish. Materialism in the age of quantum field theory is problematical.
The traditional opposition to idealism is a set piece of the nineteenth-century era of Hegel and is misleading as a generalization. The idea that idealists are reactionaries and materialists revolutionary is nonsense now, whatever sense it had in the era of the early modern. The issue of Hegel misses the point and neglects the far more foundational figure of Kant, whose work we should note was the foundation for an entire school of socialism.
The debate between idealism and materialism is a waste of time. In physics, even is the text says ‘materialism’ the equations say idealism. What is an equation in physics, an entity in an (idealist)sphere of abstractions. The mathematics of physics is a mysterious ‘ideal’ zone of ‘just in time’ innovations with uncanny timing ahead of new physics. The classic example is the mathematics of General Relativity whose mathematical basis long predated Einstein’s use of it.
Who can say anymore what is a true foundation for knowledge. Marx’s choice of economic fundamentalism was notably unsuccessful. And the example of Kantian ethical socialism, ignored by the cadre of second-rate Marxist philosophers, is clear proof that a radical/revolutionary platform can look beyond historical materialism’s poorly founded pseudo-science.
The left would do better with a large framework that can look at and embrace these opposites.
The issue of dialectical materialism is also a thing of the past. It is not a scientific stance and makes a kind of mysticism out of the dialectic.
The left needs to travel light and adopt a larger view where the issue is the history of philosophy as it is, and not the useless debate with Hegel’s idealism, a far cry from Kant’s so-called ‘transcendental idealism’.
The futile obsessions in these debates do not advance socialism so much as alienate needlessly by making dogmas out of now useless positions.

Wellred Books proudly presents the new edition of Lenin’s Materialism and Empirio-criticism. In this classic text, Lenin brilliantly explains the fundamental principles of the materialist philosophy of Marxism. He defends them against idealist attacks from the subjective idealism of Machism, a philosophical trend, which at Lenin’s time was becoming very fashionable, even within the workers’ movement.

Source: In Defence of Materialism – Alan Woods