itself. Every particular involvement-with happens on the basis of being-in-the-world. But this constantly prior being unto and in the world is also an a priori being with the world. This, by way of contrast to existence as being-in-the-world, is a very special form in which this structure is enacted, namely: As in-the-world, existence has a priori given itself away to the world in using it, exploiting it, and so on. Existence not only “is” in the world in an essential way, but also “is” fallen into the world. The world encounters us not as some indifferent “place-in-which,” where existence operates. Existential being unto the world is a matter of being essentially assigned [Angewiesensein] to the world and hence it is an a priori being-fallen into the world.
A-priori-being-with the world is neither an indifferent way of being unto the world nor a mere dwelling in it in the sense of observing it, staring at it. Rather, this with-the-world means being essentially assigned to it, being absorbed in it, operating in it as having been handed over to it. Human existence’s way of being with its world is never anything like the way things are with each other qua juxtaposed. This kind of being-with-each-other (for example, the way the chair is there with the door) is the way that two things, both of which belong to the world, are next to each other. Here too, because our language is not formed according to the rules of formal logic,  it is a bit inconsistent.
Imagine a walking stick leaning against the door or wall. One might say that the one touches the other. But on closer reflection we should not speak of “touching”—and not because we could show that there is ultimately some space between the two. Rather, on principle the walking-stick does not and never can touch the wall, even if there were absolutely no distance between it and the wall. For that to happen, the wall would have to be able to encounter, and be encountered by, the walking-stick as a thing in the world. One thing can touch another only if it is a being that—as such, intrinsically, and of its ownmost being—has its world. Only in that way can it touch another being, and only thus can the thing touched be uncovered in the touching and become accessible in its being as something there. So we see that in saying “Two things touch,” we are taking existence’s way of being unto the world and transferring it to a thing that appears within the world and therefore, in itself, is worldless.
On the other hand the ontological relations of worldly things and events can also get transferred to existence. An example of that: when we speak of the “movement” of thinking and neglect to say what “movement” means here or could mean. Most often we mention only this transference of world-oriented discourse to existence. Existence’s being-with is not, therefore, juxtaposition, i.e., a continuous or discontinuous filling up of space.
Being-with is one way the structure of being-in-the-world is enacted.