As I understand it, Heidegger asked himself what is the meaning of being? And before formulating a coherent answer, he went back to see what the philosophical tradition had to say on the matter.
He understood that tradition had predominately conceived being in terms of what is essentially the idea of Aristotelian substances
, self-sufficient entities with properties or categories. This perspective persuades one to frame being in terms of a subject-object dichotomy.
For example, and for the sake of argument, the subject could be a 'hammer' and it is predicated as, say, 'being a metal blob at one end, wood the other' etc. The upshot of substance theory leads to a twofold enquiry into being. Firstly, the search for an ultimate, or fundamental basic substance to all things; and secondly, the idea of the predicate calculus, that in theory if you can represent all the predicate-properties to all the subject-substances, you have effectively described all being.
Heidegger considered substance ontology a worthy pursuit, especially in the natural sciences, and called it presence-at-hand
, or present-at-hand
. But Heidegger realised that this kind of ontology just didn't work for all kinds of being. So, presence-at-hand couldn't be the
big O ontology.
Heidegger realised that even if you understood all the presence-at-hand
properties of the hammer, you still haven't got at what it is to be the hammer. It couldn't be a hammer, for example, if there weren't other stuff in existence, like nails, and planks of wood. Further more, there must also ibe some kind of entity with the ability and foreknow to make and use a hammer, an entity with skills, practices, values and neccessities.
Clearly, there seems to be another ontological feature to being which 2000 years of philosophical tradition had completely overlooked, namely tools or equipment, what Heidegger calls readiness-to-hand
Readiness-to-hand demonstrates that the idea of self-sufficient substances (an atomistic
perspective) is limiting. Equipment not only highlights a towards-which
(a task in hand), a final-towards-which
(the goal of that task) and for-the-sake-of-which
(the task of hammering, for example, is for the sake of housing), but also alludes to a type of being capable of making such stuff, and needing to make such stuff. The atomistic persepctive must now make room for a more holistic
understanding of being.
With an understanding of readiness-to-hand, Heidegger understood that the being which could make such equipment could neither just be present-at-hand (but could be if so desired), nor readiness-to-hand (but could be). A third feature of being was required.
If you recall, tradition had understood humans in terms of substance. For Descartes humans were essentially a mental substance called res cogitans
, for Kant humans were some kind of transcendental
substance. Even today, there are many modern philosophers such as Ryle who understand humans as a kind of thinking-intentionality-thing, we could even be brains in a vat!
Heidegger would accept none of this. We are beings whose way of being is activity, we are by taking up practices and readiness-to-hand, we take a stand on being, what it means to be and we make an issue of it through our activities. Heidegger calls this being Dasein
Being and Time Page 32.12 (Macquarrie & Robinson) "Dasein is an entity which does not just occur among other entities. Rather it is ontically distinguished by the fact that, in its very being, that being is an issue for it.
" Kierkegaard said much the same thing, just a lot more abstracted, "the self is a relation that relates itself to itself
In other words, we have some sense of what it means to be human.
3 Ways of Being
So, essentially for Heidegger there are three ways of being. Presence-at-hand; Readiness-to-hand; and Dasein. And each are modes of being. Heidegger does note that there may be other ways of understanding being, and that these ontological features may not be suitable for primitives or other cultures, so this need not be considered a universal statement, an absolute condition, just one that probably exhausts the ways of being in our cultures.
Hope this helps a little.