which speak of the immanence of consciousness and of the subject conceive of consciousness precisely in this sense of a snail-shell. But as long as the sense of the 'within' and immanence is left undefined, so that we never learn what sense this 'in' has and what relation of being this 'in' of the subject has to the world, it is at any rate in a negative way equivalent to our analogy.
We can say that the snail at times crawls out of its shell and at the same time keeps it on hand; it stretches itself out to something, to food, to some things which it finds on the ground. Does the snail thereby first enter into a relationship of being with the world? Not at all! Its act of crawling out is but a local modification of its already-being-in-the-world. Even when it is in its shell, its being is a being-outside, rightly understood. It is not in its shell like water in the glass, for it has the inside of its shell as a world which it pushes against and touches, in which it warms itself, and the like. None of this applies to the relationship of being of the water in the glass or, if it did, we would have to say even of water that it has the mode of being of Dasein, it is such that it has a world. The snail is not at the outset only in its shell and not yet in the world, a world described as standing over against it, an opposition which it broaches by first crawling out. It crawls out only insofar as its being is already to be in a world. It does not first add a world to itself by touching. Rather, it touches because its being means nothing other than to be in a world.
This applies similarly to a subject to which knowing is ascribed. If it is posited as an entity which is supposed to have this possibility of being, it is thereby understood as an entity which is in the mode of being in a world. But this positing is performed blindly, without an understanding of what in principle is already implied in knowing.
We have oriented the question of in-being in particular toward the relation of knowing because this mode of being of Dasein traditionally has priority in the philosophical determination of the relation of the ego (the subject) to the world; and yet this mode of being is still not originally conceived but instead remains the source of all sorts of confusion as a result of this indeterminacy in regard to its being. The so-called epistemological positions of idealism and realism and their varieties and mixtures are all possible only on the basis of a lack of clarity of the phenomenon of in-being, about which they formulate theories without having exposed it in advance. Idealism and realism both let the relationship of being between subject and object first emerge. Indeed, in idealism this leads to the assertion (in quite distinct ways, depending on whether it is logical or psychological idealism) that it is the subject which first of all creates the relation of being to the object. Realism, which goes along with the same absurdity, in contrary fashion says that it is the object which through causal relations first effects the relations of being to the subject. In opposition to these basically