To say that language speaks is not a mystification but an attempt to correct a picture that has dominated Western thinking since Aristotle: that language is a system of signs produced by human beings to express their inner states or refer to outer objects. On this picture, language is instrumental — it serves human communicative purposes. Heidegger argues that this picture inverts the real relationship: it is language that first discloses a world, that first allows human beings to understand themselves as existing in relation to beings, that first makes the encountering of beings possible as the encountering of beings rather than as mere stimulus-response.
Heidegger's phrase "language is the house of Being" (from the 1947 "Letter on Humanism") means that being is sheltered in language the way a human being is sheltered in a house: language is the medium within which being shows itself and within which the human being exists as a speaking being. To be human is to dwell in language, in the sense that language is not an optional instrument one might dispense with but the condition of all understanding and all existence. The human being (der Mensch) is the one who inhabits (wohnt) language — who guards and preserves the house of being.
If language is not primarily an instrument for human use but the event in which being discloses itself, then the highest human relationship to language is not mastery but stewardship: hearing what language says, following where it leads, and allowing the originary speaking of language to come through rather than overriding it with one's own communicative purposes. Poetry, for Heidegger, is the mode of language in which this originary speaking is most available: the poet does not use language to express ideas but allows language to speak — to name being and thereby call it into presence.
The formula "language is the house of Being" appears in the "Letter on Humanism" (1947). The later essays on language — "Language", "The Nature of Language", "Language in the Poem" — all collected in On the Way to Language (1959) — develop this analysis through readings of Stefan George, Trakl, and Hölderlin.
