Philosopher and historian of ideas Leszek Kołakowski pointed out that "Marx's theory is incomplete or ambiguous in many places, and could be 'applied' in many contradictory ways without manifestly infringing its principles". Specifically, he considers "the laws of dialectics" as fundamentally erroneous, stating that some are "truisms with no specific Marxist content", others "philosophical dogmas that cannot be proved by scientific means" and some just "nonsense". He believes that some Marxist laws can be interpreted differently, but that these interpretations still in general fall into one of the two categories of error.