Being and Time

Chapter-by-chapter summary

Being and Time has an introduction and two divisions of six chapters each. It is unfinished: only the first two divisions of the planned Part One were published.

Introduction, Chapter 1: The necessity of asking the question of being

Heidegger opens by saying that the question of what 'being' means has been forgotten. Philosophers treat 'being' as the emptiest, most obvious word, so they stop asking about it. He disagrees: we use 'is' all the time and understand it in some vague way, which is exactly why it needs examination. He adds that the question has a special structure, because the one asking is also a being. This matters because it sets the book's method: to understand being, start by studying the being that questions.

Introduction, Chapter 2: The twofold task

Heidegger sets out a two-part plan. First, analyse the being of Dasein to prepare the question of being, and show how time lets us understand being at all. Second, work back through the history of philosophy to uncover how earlier thinkers covered over that question. He calls this second job a 'destruction' of the tradition, meaning a careful taking apart to find what it grew from, not a demolition. His method is phenomenology: letting things show themselves as they are. The plan explains the book's structure, and also why it is unfinished.

Division One, Chapter 1: Preparing the analysis of Dasein

Here Heidegger introduces Dasein, his word for the kind of being that humans have. Dasein is the being for whom its own existence is an issue: we do not just exist, we have to live out some way of existing. Two features follow. Dasein's 'essence' lies in its existing, not in a fixed definition, and each Dasein is always 'mine'. He also warns against treating humans as objects, minds or animals with extras, since those pictures hide how we actually live.

Division One, Chapter 2: Being-in-the-world

Heidegger argues that 'being-in-the-world' is a single unified phenomenon, not a mind sitting inside a body inside a room. To be in the world is to be involved with it, dwelling and dealing rather than staring. He shows that the traditional puzzle of how a subject reaches an outside world is a false problem, because we are never cut off from the world to begin with. The chapter sets up three aspects of the structure: the world, who is in it, and what being-in itself means. Later chapters take these in turn.

Division One, Chapter 3: The worldliness of the world

This chapter works through the famous tool analysis. We meet things first as equipment, such as a hammer used for hammering, and only later as bare objects with properties. Equipment works inside a web of purposes, and we notice it mainly when it breaks or goes missing. Heidegger contrasts this 'ready-to-hand' use with the 'present-at-hand' stance of detached observation, and criticises Descartes for treating the world as extended substance. The point is that meaning comes from practical involvement before theory.

Division One, Chapter 4: Being-with and the 'they'

Other people are not added to the world afterwards: Dasein is always being-with. In ordinary life, however, we mostly live as 'das Man', the 'they': we do what one does, think what one thinks, and read what one reads. This anonymous averageness takes responsibility off us and levels everything down. Heidegger describes it as a basic feature of everyday life, not a moral failing of some people. It matters because it explains why a person's own self is usually hidden and has to be won back.

Division One, Chapter 5: Being-in as such

Heidegger examines what it means to be 'in' the world through three structures. Attunement, or mood, shows that things already matter to us before we reflect. Understanding is our ability to project possibilities, to see what we can do. Discourse, or talk, gives these a shape in language. He then describes how everyday life falls into idle talk, curiosity and ambiguity, which keep us busy on the surface. The chapter shows that thinking comes after a world has already been opened up by mood and understanding.

Division One, Chapter 6: Care as the being of Dasein

Heidegger gathers the earlier findings under one word: care (Sorge). Dasein is ahead of itself, already in a world, and involved with things at hand. Anxiety, a mood in which the familiar world feels strangely empty, reveals this whole structure by pulling us away from the comfortable 'they'. He backs the claim with an ancient fable in which the goddess Care shapes the first human. The chapter closes the first division and leaves one question: how can Dasein be seen as a whole?

Division Two, Chapter 1: Being-toward-death

To see Dasein as a whole, Heidegger has to include its end. He argues that death is not just something that happens at the end of a life but a way of being that shapes every moment: Dasein is always 'toward' its death. Death is mine alone, cannot be handed to anyone, and cannot be got past. Everyday talk covers this over by treating death as something that happens to 'one'. Facing it honestly, rather than waiting for it as an event, is what opens an authentic life.

Division Two, Chapter 2: Conscience, guilt and resoluteness

Next Heidegger asks whether Dasein itself bears witness to an authentic way of being. He finds that witness in conscience, which he reads as a silent call from Dasein to itself, away from the 'they'. Hearing it means accepting a basic guilt: we never choose the grounds of our own existence, yet we must take responsibility for it. This is not moral guilt. The answer to the call is resoluteness, a clear-sighted readiness to act on one's own possibilities. It is not a moral code but a description of owning one's life.

Division Two, Chapter 3: Temporality as the meaning of care

Here the argument reaches its centre. The structure of care turns out to be time itself: Dasein comes toward itself from the future, takes over what it has been, and acts in a present. Heidegger calls this unity 'temporality' and argues it is more basic than clock time. Authentic Dasein holds the three together; inauthentic Dasein drifts in the present. This is the book's answer to its opening question as far as it goes: time is the horizon in which being can be understood, though the full proof was never given.

Division Two, Chapter 4: Temporality and everydayness

Heidegger returns to the themes of Division One and re-reads them through time. Understanding is linked with the future, mood with the past, and falling, the drift into the 'they', with the present. Idle talk, curiosity and busy absorption in tasks turn out to be ways of being in time. The chapter shows the book's logic: the earlier analysis was not wrong but only half visible until time was brought in.

Division Two, Chapter 5: Temporality and historicality

What does it mean to have a history? Heidegger argues that Dasein does not sit inside history like an object in a box; it is historical because it stretches between birth and death and inherits a past. People take over possibilities from their community, and 'fate' means choosing among them with resolve. History as an academic science therefore depends on this deeper historicality. He also discusses how we pick figures from the past as models to repeat. The chapter ties individual existence to shared tradition.

Division Two, Chapter 6: Temporality and within-time-ness

The last chapter explains how ordinary clock time arises. Because Dasein is concerned with the world, it dates events ('when the shop opens') and measures them with the sun, calendars and watches. Heidegger argues that this public, countable time is derived from the deeper temporality, not the other way round. The book breaks off with open questions about whether there is a way from original time to the meaning of being. Those questions were left for the parts that were never published.

Key people and terms

• Dasein: Heidegger's word for human existence, literally 'being-there'. It names the being that can ask about being, and stresses that we are always situated in a world rather than floating above it as observers.
• Being-in-the-world: The basic structure of Dasein. We are already involved with things, places and people before we study them, and knowing grows out of that involvement, not the other way round.
• The 'they' (das Man): The anonymous average that tells us what one does and thinks. Everyday life mostly runs on it, which brings ease and shared meaning but hides personal responsibility. It is a structure of life, not a group of people.
• Care (Sorge): Heidegger's name for the unity of Dasein's being: being ahead of itself, already in a world, and involved with things. It is closer to 'it matters to me' than to worry.
• Anxiety (Angst): A mood without a particular object, in which the familiar world feels empty. It pulls Dasein away from the 'they' and reveals that its own existence is at stake.
• Being-toward-death: The way Dasein relates to its own end throughout life. Death is the possibility that is mine alone, cannot be shared and cannot be passed on, so it gives life its shape.
• Authenticity and resoluteness: Authenticity means owning one's existence instead of drifting with the 'they'. Resoluteness is the clear readiness to act on one's own possibilities, with open eyes about one's limits.
• Temporality: The structure of future, past and present that Heidegger finds beneath care. He treats it as more original than clock time and as the horizon for understanding being. It is the book's key concept.
• Edmund Husserl: German philosopher (1859–1938), founder of phenomenology and Heidegger's teacher. Being and Time is dedicated to him and keeps his method of describing experience, though it changes its aims.

Applying the ideas

Heidegger did not write a self-help book, and the ideas do not come with instructions. They can still change how you look at ordinary things.

• Watch your tools. Notice what you stop seeing when it works, such as your phone, your language or your routine, and what you see when it fails.
• Check the 'they'. Before you adopt an opinion or a plan, ask whether you chose it or simply picked it up from the people around you.
• Read moods as information. A mood tells you how things matter to you before you have reasons.
• Let finitude clarify. Thinking honestly about limited time can sort urgent things from merely loud ones.

For a first read, take Division One slowly and keep a glossary of the German terms. Common English translations are by John Macquarrie and Edward Robinson (1962) and by Joan Stambaugh (1996, revised 2010). The two use different words for some terms, so stick with one while you read. Remember that the book is unfinished, and treat the final chapters as a starting point for later work, not a closed system.