Heidegger’s philosophical interests were originally stimulated by reading canonical figures such as Aristotle and Kant, but he was also inspired by Kierkegaard and Nietzsche, who at the time were not really regarded as philosophers. They were deeply critical of the philosophical tradition, especially in the form of what Nietzsche called “Platonism.” Heidegger too adopted a critical perspective on what he saw as insufficiently examined presuppositions of Western philosophy.
The reflections stimulated by these thinkers (along with Dilthey and Husserl, to whom Heidegger was an assistant) culminated, by some extraordinarily original process of philosophical imagination, in Being and Time (1927).
In the late 1930s and early 1940s, a “turn” (Kehre) took place in Heidegger’s thinking, which is reflected in his “Letter on Humanism” (1947).
Fundamental ontology. In Being and Time, Heidegger is attempting a “fundamental ontology” – that is, he’s trying to grasp the basic semantic root of the various ways we understand what it is to be. Roughly, his answer is that to be is to be taken as being something, to be present or to “show up” to a human being. This depends in turn on the temporal unity that characterizes our “being-in-the-world” – the way in which, wherever and whenever human beings are, they find themselves dealing with a situation involving things, goals, practices, and people that matter to them.
In undertaking his inquiry into the meaning of Being, Heidegger believes he is formulating a problem that is (a) deeply significant and (b) until him, unappreciated. Philosophy has always asked questions about beings, such as: Is there a God? Is He omniscient? Does the external world exist? Do other minds exist? Science, too, investigates beings: What are the atomic and molecular structures of matter? What causes sodium and chlorine to bond? But in asking whether certain kinds of beings exist, and which properties they possess, philosophers and scientists ignore the question of what it is for something to exist in the first place.
The ontological difference. When we ask that question, it turns out that the meaning of being is both ambiguous (it can mean many things) and vague (its meanings are not clear or self-evident). Existence is what all existing things have in common, but existence itself is not a thing and so can’t be understood the way we understand things in general, as objects with properties. So not only have philosophers failed to pose the question of being, when we do pose the question it turns out that it’s not at all clear how to go about asking and answering it. Nevertheless, it’s a central problem – what could be more significant than the question of what it means for something to be?
In exploring the matter, Heidegger says, we must keep in mind the “ontological difference”: the difference between beings or entities and what it means to be (the “Being” of beings). Treating Being as if it were a being, it turns out, is the basic flaw of Western metaphysics since Plato, so one aspect of Heidegger’s project is to work out the history and consequences of this “forgetting of Being.”
At bottom, Heidegger is interested in the phenomenon of intelligibility. What is it for the world to make sense? How does sense or meaningfulness come to be? In Being and Time Heidegger calls the source of intelligibility Dasein (the German word for existence), which is something like the human way of being: not as a living creature, not as an individual agent, but as the bearer of practices, dispositions, and concerns shared with others – for instance, as the speaker of a shared language, which is something that becomes centrally important to Heidegger after Being and Time.
There’s a great deal to say about how this project plays out, putting it mildly. I’m going to ignore most of it because from here on in things become controversial (in fact, they already have). I won’t say anything (or anything much) about the Kehre, but I’ll hazard a bit more on Being and Time.
Being-in-the-world. As I said, Heidegger trains his attention on “the being for whom Being is an issue,” namely Dasein, or us. What are our most fundamental ways of sense-making, those universally shared by human beings? Heidegger develops the idea that in order for beings to show up for us as beings, we ourselves must be open to encountering them. We are essentially “Being-in-the-world,” which entails “Being-with” others in a totality of involvements such that we use particular things (“equipment”) in definite contexts (“in-which”) to take a step (“in-order-to”) that contributes to a completed task (“towards-which”) understood as relevant to actualizing a possible way for us to be (“for-the-sake-of-which”).
Thus I might press on the brake and start button of the car (equipment) in my driveway (in-which), to start the car and drive to Stanford (in-order-to), to teach a class (towards-which), all as part of my being a teacher (for-the-sake-of-which).
Authenticity. Typically, we are simply absorbed in such activities and are not consciously thinking about them or ourselves as individuals, so long as things are going well. When things go wrong, however, we may find ourselves standing outside the world, as it were, momentarily seeing it as a whole in order to grasp where the problem lies and to re-establish our trouble-free involvement. Things can go wrong mechanically, as when a piece of equipment malfunctions. For example, my car might not start because the battery is dead, at which point the world as a whole comes into view and various courses of action present themselves to me: recharge the battery, borrow my wife’s car, get a ride with a friend, ask a colleague to teach the class, cancel the class, etc.
But things can also go wrong “existentially”: we sometimes find that the world we thought was ours no longer makes sense. I can have the feeling that whether or not the class gets taught doesn’t really matter. Am I really a teacher – is that really my calling? This kind of thing makes us anxious, but it also presents an opportunity for us to understand ourselves “authentically,” as unique individuals who can own up to who we are by resolving to take responsibility for ourselves. When I say in response to the mood I described “Yes, it is my calling,” I also realize that each and every moment of my life was and is an opportunity to do the same.
When we are inauthentically or non-authentically going about our business in an un-self-conscious and un-individuated way, we casually take responsibility for what we’re doing at any given time. I understand that I’m responsible for preparing my class, setting out for the campus on time, and getting home again, just as I’m responsible for returning a book to the library when it’s due or waiting for the light to turn green before crossing the street.
But when in a state of anxiety I wonder whether any of this really matters, I have the opportunity to assume responsibility for my entire life, my life as a whole. At such moments we understand that we are “nothing but” the totality of our choices and actions and that we are responsible not merely for what we do, but also for who we are. Authenticity is owning up to this understanding such that it informs and is exhibited in everything we do.
Temporality and mortality. Crucially, “going authentic” involves grasping the peculiar condition of temporality. Wherever and whenever we find ourselves, we are projecting ourselves into the future by understanding what we are presently doing in terms of an expected outcome. What we are presently doing, however, is exercising abilities and purposes we already acquired in the past. To be present is to have drawn the past into the present and projected it into the future as a possibility that will become actual. At its most basic, then, temporality is a unified mode of Being, but different aspects – past, present, or future – typically “stand out” for us at different moments. We grasp temporality as a whole, however, when we understand that there is one possibility that will never be actual for us, namely our death, since when that becomes actual we will no longer be.
In this way we see that our death is always present in that we are mortal, that each individual’s mortality is uniquely his or hers, and that we are in a position to take ownership of our lives and approach them authentically.
Misconceptions. One misconception that might stem from what I’ve written so far is that Heidegger was mainly preoccupied with “existential” issues. This is the aspect of Heidegger that people like Jean-Paul Sartre fixated on. But for Heidegger, the existential analysis of Dasein was a means to the end of asking about the meaning of Being. In the “Letter on Humanism” and other writings, Heidegger de-emphasizes things like authenticity in favor of the more basic theme of openness to beings as exhibited in language, artworks, poetry, and things.
Reality. A common misconception is that when Heidegger talks about Being, he means that something exists. In fact, he means the intelligibility of beings as that which we take them to be. If you ignore this distinction, you can fall into thinking of Heidegger as a kind of idealist who believes that there are no natural or objective entities apart from our understanding of them, or worse, that natural entities depend on our understanding of them. The point can seem paradoxical. That there are natural entities that exist independently of our understanding of them is, of course, our way of understanding what natural entities are. Their non-dependence on us matters to us, not to them. In a sense, naturally occurring entities in themselves neither are nor are not independent. But it is emphatically the case that natural entities exist independently of us. There were dinosaurs that existed before us, but dinosaurs were not intelligible – they could not be taken as dinosaurs – until we so took them. That doesn’t imply that there were no dinosaurs – dinosaurs is precisely what there were.
Agency. Relatedly, the fact that the Being of entities is a matter of our taking them as such doesn’t imply that we are free to take them in any manner we please. On the contrary, who we are and can be is conditioned by how entities can show up to us. I am a carpenter only insofar as hammers and nails show up to me as ready-to-hand, i.e. only insofar as I can skillfully make use of them. In real life, hammers and nails will not disclose themselves to me as ready-to-hand. Taking something as something doesn’t mean forming certain beliefs about it. It is not primarily a mental act. It’s a way of being involved with something. (Part of what limits what can be disclosed to me is the interpretation of Being shared by the particular culture or community or historical period to which I belong. This suggests that different periods can have different understandings of Being, something that Heidegger explores at length.)
Truth. It’s also easy to misconstrue Heidegger’s criticisms of the correspondence theory of truth to mean that there’s no such thing as a proposition that may or may not be true, i.e. correspond to the way the world is. In fact, his view is that the relationship of correspondence depends on the more basic structures of intelligibility that he articulates in Being and Time and elsewhere. Before there can be propositions that do or do not correspond with the objects to which they refer, there must be a world in which both propositions and objects can be taken as such. To say that that world does or doesn’t correspond to reality makes no sense, because reality – whatever reality Dasein can encounter – just is that world. Analogously, the various factual sentences we can form in English either are or are not true, but it makes no sense to ask whether the English language as a whole is true or false. None of these considerations, however, implies that there is no fact of the matter as to whether utterances like “Snow is white” and “The cat is on the mat” are true or false.
Heidegger’s life. Unfortunately, it’s important to know that Heidegger was a Nazi. He joined the Nazi Party in 1933. There’s a great deal of controversy over the extent of his involvement with the Nazis and the nature of that involvement, and especially over the relationship of his politics to his philosophical work.
Below, Heidegger in the 1930s.
Heidegger doing what he did best: