ImmanuelKant (1724- 1804) distinguished between “phenomena” and “noumena”.
Phenomena are things that we perceive though our senses and understand by applying our reason to them. But Kant believed that objects also have an existence in themselves which we cannot directly experience. This is “noumena” or the “noumenal world”.
Edmund Husserl (1859-1938) agreed that human beings are, by nature, subjects that view or perceive objects. Our consciousness always involves perception “of something”. For Husserl the fact that we clearly do perceive or experience the external world as phenomena means that these perceptions could be a fruitful area of study. This is the philosophy referred to as “phenomenology”. Husserl did not necessarily disagree with Kant’s notion that we cannot directly experience the existence of an object “in itself”. But he was simply prepared to set that issue to one side or to “bracket” it.
Martin Heidegger (1889-1976), was a student of Husserl. But he departed from the view that human beings are primarily subjects observing the world. Heidegger emphasised that we ourselves are part of the world. We are primarily “coping beings”.
Whereas Husserl emphasized consciousness, Heidegger emphasizes existence. The world and external existence is not something that needs to be proved by philosophical inquiry because we are “beings in the world”. We are beings who are already in the world, a world from which, for the most part, we do not distinguish ourselves.
Heidegger, who was an atheist, also emphasized that our existence occurs within time in the stretch between birth and death. For Heidegger, the constant fear of death and the anxieties of life lead human beings to ask a central question “what is it to be?” Heidegger elaborates these ideas over the 437 pages of his book “Being and Time”.
Heidegger is often described as the most important and influential philosopher in the continental tradition in the 20th century. According to the Internet Encyclopaedia of Philosophy:
“Heidegger exercised an unparalleled influence on modern thought. Without knowledge of his work recent developments in modern European philosophy (Sartre, Arendt, Marcuse, Derrida, Foucault et al.) simply do not make sense.”
But Heidegger’s central idea bears striking resemblance to Karl Marx’s famous statement “philosophers have only interpreted the world…the point is to change it.”
Heidegger commented directly on this statement by Marx in an interview on German television. Heidegger claimed that in this statement Marx overlooks the fact that the possibility of changing the world presupposes a conception of the world and a sufficient interpretation of it. Heidegger suggests this is a deliberately false statement by Marx as part of a polemical attack on philosophy.
But it is clear from other things that Marx wrote that he viewed human beings as existing in a material world with which they must interact. This really means that we cannot help but change the world. This occurs both at an individual and social level. But there is no doubt that for Marx the most important level was the social level and the process of production in particular. Production occurs in every different type of society and is essential to sustaining human life. It cannot be avoided.
Marx wants to draw attention to the primacy of practical action:
“All social life is essentially practical. All mysteries which lead theory to mysticism find their rational solution in human practice and in the comprehension of this practice.”
Just as Heidegger said after him, Marx is saying that the way human beings exist is not as separate subjects observing and interpreting objects. Rather we necessarily exist in the world and in the process of interacting with it, especially through production, we necessarily change it. It is true that we end up interpreting the world through consciousness. But the way we do so, our belief systems, are themselves influenced by practice, rather than the other way around. The strongest influence on our consciousness is the way that the system of production is arranged and the social institutions that form around this system.
Perhaps Marx’s famous statement would have been better had he stated of the world “philosophers have only interpreted the world…the point is that we change it” instead of “the point is to change it”. But Marx was also a polemicist interested in the circumstances that might result in a radical rearrangement of the system of production.
In any event, it is abundantly clear that Marx’s starting position is human beings existing as part of the material world, not separate from it.
It is also true that Marx was more interested in social life than individual life. So, unlike Heidegger, he did not spend time on the issue of how individual anxiety about death might lead to the question “what is it to be?” Indeed he might have regarded such a preoccupation as being a waste of time.
But surely, like Heidegger Marx’s starting point is being, not consciousness. And surely he arrived at this position well before Heidegger.