Post-modernism rejects categories like cause and effect. Marxism believes that cause always precedes effect, but succession in time is not the adequate sign of cause. For example, day follows night, but night is not the cause of day. Here comes the question of rotation of the earth. No phenomenon exists or can exist without cause, for everything has its cause. Causality is inherent in reality and is discovered by man in the process of cognition and practical activity.

Post-modernism rejects categories like cause and effect but Marxists believe that the categories of Marxist dialectics are a result, generalisation of the centuries-old experience of people, of their labour and knowledge. In course of his practical activity man, coming in contact with, and cognizing objects and phenomena of the world, has singled out their essential, general features and fixed the results in categories, concepts. Lenin wrote "Instinctive man, the savage, does not distinguish himself from nature. Conscious man does distinguish: categories are stages of distinguishing, i.e., of cognizing the world."[Lenin, Collected Works, Vol.38, p.93]

Categories like cause and effect are stepping stones of knowledge to help people to find their way in the intricate web of phenomena in nature and society, to reveal the interconnection and interdependence of things, the definite order and the law-governed character of their development and to choose the right course of practical activity.

Marxism rejects idealism which denies the objective character of categories. Kant thought that before man begins to know the world his consciousness contains categories of causality, necessity, chance, etc. With the help of which he allegedly introduces order into the chaotic world of natural phenomena. Marxism refutes such a view and posits categories in the realm of objective reality. Secondly, categories are interconnected, changeable and mobile, being reflection of the material world, the universal connections and interactions of its objects and phenomena. The connection of categories is so close that under certain conditions they can turn one into the another. Thus cause becomes effect and vice versa, necessity becomes chance and so on.

Post-modernism/Post-structuralism rejects three pillars of Marxism, its epistemology, social totality and class. It rejects causality involving the elements of cause and effect. It states that ‘cause producing effects’ — this sequential and logical order is the fundamental principle of the essentialist concept of causality. By essentialism it is meant, they argue, the hierarchical oppositions between reality and appearance, between essence and accident, between economic and non-economic, between inside and outside and so on. The post-modern/post-structuralist trend rejects prioritising one against the other considering such act as essentialist. Thus, it rejects causality behind effects or for that matter the Hegelian thesis — antithesis — synthesis triad. Derrida argues that elements in a structure having hierarchised i.e. some having more importance than the other is, what he calls, logocentrism. Derrida thus attacks such logo centrism targeting: (1) the prior or originary element — that which causes — is autonomous. (2) An element is determined by the other elements (3) the factor, like the forces of production, that is considered to be the most important factor. Post-modernists/post-structuralists reject any foundational concept, originary base, the causation of one elements having privileged position over the causation of other elements, etc. They smell essentialism, ‘logo centrism’, reductionism, etc. in cause-effect, in the stress on principal contradiction, principal aspects of a contradiction and on all such Marxist fundamentals.

Cause and effect have a dialectical relation in which one influences the other. The superstructure (effect) comprising political, moral, religious, cultural aspects are generally the products of the mode of production (cause) continuously exerting impact on the cause. Cause and effect can also mutually change their positions. The cause in one context can become effect in some other context. Effect also can turn into cause. From the Marxist point of totality, it is found that every cause can be an effect and every effect can be a cause. Marxism also holds the view on the presence of internal cause, basic causes and principal cause. There is difference between the complete cause and the specific cause. The former is the sum total of all the circumstances, the presence of which necessarily gives rise to the effect. The specific cause is the sum total of circumstances, the presence of which (with the presence of many other circumstances already present in the given situation even before the conditions for the action of the cause) leads to the appearance of the effect. The establishment of a complete cause is possible in comparatively simple cases and generally scientific investigation proceeds towards the comprehension of the specific causes of the phenomenon.

Post-modernists reject the question of cause causing effect. They often refer to their guru Nietzche who in his The Will to Power gives the example of pin and pain. I feel pain. Immediately, I look for a cause, i.e. the pin. Thus pin is the cause, pain is effect. Nietzche changes the order. He says that my experience of pain causes me to look for the cause (pin), thus causes the production cause. Pain becomes the cause while pin the effect of the cause. This way Nietzche wants to prove that the cause becomes the effect, while effect the cause. With this example, Nietzche and his followers claim to have destroyed the cause-effect sequence and also the position of origin. This is metaphysics, simple and pure, an obstinate effort to dismiss the cause-effect sequence. Instead of pin if we take a mosquito bite/snake-bite and the resultant painful suffering/death, our post-modernist idealist doctor with his Nietzchean view will pinpoint the latter as the cause of the former and burst into frenzied glee for the supposed, dismissal of the point of origin. Such absurd idealist view will in turn exonerate imperialists, capitalists, etc. as cause for plunders and exploitation. In the name of logo centrism or essentialism such idealist thinkers reject giving privileged status to certain factors/elements and thus dismiss the Marxian dialectical view that the causative factors, like the forces of production and relations of production, generally play a more important role than other elements in the socio-economic process. They are stubborn in their allowing equal status to all elements with the rejection of the cause-effect sequence. This is also Derridean deconstruction, the deconstruction of dependency, origin and foundation. Against such an absurd view of befogging the socio-economic process, Marxism holds that there are both internal and external contradictions with the internal generally remaining as basic. Nevertheless, at times external contradiction plays a decisive role. It is not the role of the social scientist to leave the stage imparting equal importance to all the factors in a given moment; rather it is his duty to study the contradictions in order to grasp the principal, main and less important contradictions at a given moment. In the name of reversal cause-effect sequence, giving equal status to all the factors and dismissing the originary point, post-modernists/post-structuralists actually want us to keep our eyes closed to the principal imperialist powers, the basic classes of revolution, the principal contradiction in a country in a given period, etc. Such views can raise a furore over a tea cup in a coffee house or academic institution, but becomes dangerous opium in the real life struggle of the masses.