Heidegger made his first public appearance on December 1, 1949, at the unlikely venue of a gentlemen’s club in Bremen, founded in 1781. Under the overall title of Insight into What Is (GA 79), he presented the fruits of his thinking since 1935 in four lectures:

1 The Thing (Das Ding).
2 The Framework (Das Ge—stell).
3 The Danger (Die Gefahr).
4 The Turning (Die Kehre).

These presentations contained the substance of Heidegger’s mature philosophy, and although Heidegger continued to think, write, and speak for another twenty—seven years, little regarding technology was added. As before, his writings on being, thinking, language, poetry, and some of his great predecessors by far outweighed in quantity what he said and published on technology after the war, and it is this massive material that has chiefly concerned the Heideggerians and postmodernists. But his enduring legacy may well he his insights into the framework of technology and his reminders of the fourfold nature of the thing.

Remarkably, Heidegger seems to have been unsure of the cohesiveness and persuasiveness of the Bremen lectures, for he never had them published as a whole during his lifetime. In 1954, he published the second lecture under the title "The Question Concerning Technology" and the first under he same title, "The Thing," in a collection of essays. However, these two Bremen lectures were grouped in different parts of the anthology and out of sequence, and without any indication of their original connection, "The Question Concerning Technology" was rendered in English in 1977 in an unfortunate translation that has given us the neologisms of “enframing’ (das Gestell, better the framework) and “standing-reserve” (der Bestand, better resources).
[...]
In 1962, Heidegger once more published "The Question Concerning Technology," this time under separate cover along with the fourth Bremen lecture, "The Turn." In the prefatory remark he acknowledges their origin in the Bremen lectures. Of "The Question" he says that it is an enlarged version of the second lecture. The fourth lecture, "The Turn," is unchanged, he says further. We can now see that his last remark is accurate. "The Question," however, though enlarged in some tarts (parts one and two, for example), is quite different, from "The Framework" (das Ge—Stell) in the Bremen version.

"The Question" is entirely rewritten. There are only a few verbatim sentences left from "The Framework." Compared with “The Framework.” “The Question” is less immediate. less impassioned, less involved in its terminology and innocent of all the direct references to "The Thing." Heidegger must have been concerned to publish a measured and simplified analysis of technology that was not susceptible to easy dismissal on the grounds that his presentation of technology was hopelessly mixed up with a nostalgic invocation of a thing and a world that were irrevocably past. Nor did he want to be accused of cultural prejudice and partisanship.
[...]
In the prefatory remark to the 1962 edition. Heidegger claimed that the Bremen lecture "The Danger" "remains unpublished". But the crucial part was in fact incorporated in "The Question." What Heidegger tellingly omitted was the danger that lay in the "refusal of world" that comes to pass "as the neglect of the thing". It Is not only the unwelcome mention of the thing that made Heidegger think better of including this part. The German for "neglect," die Venwahrlosung, derives from a verb that means "to run down," "to mistreat," "to make shabby" This was the kind of anger and distress that Heidegger wanted to avoid (although here. as in Being and Time, Heidegger, having introduced a damning vocable, immediately denies that it carries a "value judgement").
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The objection that "The Question" concludes with an unsatisfactory answer and that the thing in his eminent sense rather than art should be the reply to the danger of technology might have mattered more to Heidegger. In fact, eight years after the first publication of “The Question,” he added the concluding Bremen lecture, "The Turn," to the reprinting of "The Question." The last Bremen lecture asserts a close connection between the framework of technology and the fourfold of the thing (and Heidegger inserted a direct reference to "The Thing" in "The Turn").

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¶ 8:52 AM