Martin Heidegger:

Heidegger claims that there has been no progress in philosophy since the Aristotelian theory of time: all successive philosophers (especially Kant) reenacted variations on that theory.

A phenomenon is "what shows itself in itself", i.e. self-showing. Phenomenology is not a theory but a method. Ontology is "the science of being of beings". The phenomenology of Dase-in is hermeneutics, i.e. interpretation.

The book is divided into two parts. Part 1 is (quote) "The interpretation of Dasein in terms of temporality and the explication of time as the transcendental horizon of the question of being"; in other words, gibberish.

Heidegger begins this first part in earnest with the amusing analysis of "the world in its worldliness", followed by "being in the world" (the Dase-in basic constitution, which cannot be broken down into components, it is an indivisible whole) as being a self and being with others", and then with a mysterious "being-in" which is not Dase-in but it is its "existential expression". and it is not clear how it relates to the previously defined (?) "being in the world". (No, i'm not making this up). Heidegger emphasizes the priority of "existentia" over "essentia" (the "what" of things). A person is not a thing. Nor is it a "psychical being". Anthropology, psychology and biology all fail to provide an adequate definition of what kind of being we persons are.

This review will mostly simply quote statements from Heidegger's book. You can make what you like of them. If you read 100 reviews of this book, you will read 100 different interpretations of what these statements means. To me, they mean absolutely nothing.

Here are some statements about being and space.

• "Being-in-the-world is the basic constitution of Dasein"
• "As Being-in-the-world, Dasein has always already discovered a world."
• "Space is not in the subject, nor is the world in space."
• "Space is not to be found in the subject, nor does the subject observe the world as if that world were in space".

Here are some statements about being and the other.

• Dase-in is essentially for the sake of others.
• Dase-in is essentially "being with".
• Everyone is the other and noone is himself.
• The Self of everyday Dasein is the they-self,
• The "they", which provides the answer to the question of the "who" of everyday Dasein, is the "nobody" to whom every Dasein has already surrendered itself in Being- among-one-other.
• The "they" is an existential; and, as a primordial phenomenon, it belongs to Dasein's positive constitution
• The Self of everyday Dasein is the "they-self" which we distinguish from the authentic Self

About being and the "there":

• Throwness: the Dasein, as Being-in-the-world, is the "there"
• The Dasein, existing, is the "there"
• Heidegger then analyzes one particular state of mind, fear
• Understanding is a fundamental mode of the being of the Dase-in
• Interpretation (not sure how it differs from understanding - maybe "appropriating what is understood") is grounded in expectation ("fore-having, fore-sight, fore-conception")
• "Meaning is the "upon-which" of a projection in terms of which something becomes intelligible as something; it gets it structure from a fore-having, a fore-sight, and a fore-conception."
• The fundamental exisentials which constitute the Being of the "there", the disclosedness of Being-in-the-world, are attunement and understanding.
• Discourse is existentially equiprimordial with attunement and understanding.
• "Discourse is constitutive for the being of the there"
• "Discourse constitutes the disclosedness of Dasein"
• "The human being... is in the mode of discovering the world and Dasein itself"
• Heidegger then turns to the "everydayness" of Dasein
• "Idle talk, curiosity and ambiguity characterize the way in which Dasein is its there... they constitute its being". They reveal the entanglement of Dasein.
• The Dasein is for the most part together with the world that it cares for.
• The disclosedness of Dasein consists in attunement, understanding and entanglement; manifests itself in everyday life as idle talk, curiosity and ambiguity.
• Heidegger then analyzes the state of mind of angst and concludes that angst "is about the world as such"

• Dasein is a being that is concerned in (cares for) its being about a being-in-the-world (Dasein is concerned with understanding of being)
• It is impossible to prove the objective existence of things outside of us.
• Traditionally, truth has been defined as the agreement of knowledge with its object. Heidegger instead defines truth as a process of discovery: a statement is true when it discovers the beings in themselves.
• Therefore truth depends on the existence of a caring Dasein. "Before Dasein there was no truth... Before Newton's laws were discovered they were not true". Eternal truths can exist only if the Dasein is eternal.
• Being and truth are equiprimordial: there is being only insofar as there is truth.
• Dasein's "totality of being" is care
• The there causes the disclosedness of Dasein that reveals care as the fundamental character of Dasein
• "Dasein understands itself in terms of what it encounters in the surrounding world and what it circumspectly takes care of "
• "The being of Dasein is care"
• Heidegger admits that he still hasn't showed the meaning of being.

• Conscience (the moral being) is Dasein summoning Dasein about caring
• The I is the being that one is in being-in-the-world. "I means the being
• that is concerned about (cares for) the being of the being which it is".
• "Temporality constitutes the disclosedness of the there."
• The care that constitutes the meaning of the being of Dasein can be reformulated in terms of expectation of death.
• Temporality is the meaning of being of Dasein.

I don't know if this book had anything to say or it was merely a giant bluff, but i know that it doesn't prove anything. Heidegger provides no proof whatsoever for what he claims. Even if he is saying something, he doesn't prove it. So it becomes a little pointless to try to figure out what he said.

To me Heidegger's convoluted and unscientific style seems to have more in common with psychiatrists than philosophers. I shudder at his grotesquely naive analyses of existence, fear, anxiety, the uncanny, conscience and death.

If you pick up this book at a library or at a second-hand bookshop, you will notice that only the first few pages have annotations and bear signs of having actually being turned. Virtually nobody had ever read this book to the end. But it is routinely listed as a milestone of philosophy. I personally think it represents a milestone of everything that gives philosophers a bad reputation: unscientific, incomprehensible, incompetent, and, ultimately, just plain silly.

Be suspicious of any philosopher who hailed this as a great book. Heidegger stated that Sartre had misunderstood most of his ideas, and that's the biggest compliment ever paid to Sartre.