Criticisms of Marxism have come from various political ideologies and academic disciplines.
These include general criticisms about lack of internal consistency, criticisms related to historical materialism, that it is a type of historical determinism, the necessity of suppression of individual rights, issues with the implementation of communism and economic issues such as the distortion or absence of price signals, and reduced incentives. In addition empirical and epistemological problems are frequently identified.
According to Leszek Kołakowski, the laws of dialectics at the very base of Marxism are fundamentally flawed: some are "truisms with no specific Marxist content", others "philosophical dogmas that cannot be proved by scientific means", yet others just "nonsense"; some Marxist "laws" are vague and can be interpreted differently, but these interpretations generally fall into one of the aforementioned categories of flaws as well.
Economist Thomas Sowell wrote in 1985:
What Marx accomplished was to produce such a comprehensive, dramatic, and fascinating vision that it could withstand innumerable empirical contradictions, logical refutations, and moral revulsions at its effects. The Marxian vision took the overwhelming complexity of the real world and made the parts fall into place, in a way that was intellectually exhilarating and conferred such a sense of moral superiority that opponents could be simply labelled and dismissed as moral lepers or blind reactionaries. Marxism was – and remains – a mighty instrument for the acquisition and maintenance of political power.
Democratic socialists and social democrats reject the idea that socialism can be accomplished only through class conflict and a proletarian revolution. Many anarchists reject the need for a transitory state phase. Some thinkers have rejected the fundamentals of Marxist theory, such as historical materialism and the labour theory of value, and gone on to criticise capitalism – and advocate socialism – using other arguments.