There’s a difference between teaching what Heidegger thinks (explicating his texts as stances) and teaching Heidegger thinking (explicating his texts as practices).
All of his lecture course transcripts are exemplifications of his sense of teaching relative to the text or topic of his lectures.
The lectures exemplify the thinking that was most important to him. The exemplarity of the lectures displays what the work (“ways,” he insisted), published during his lifetime, carefully discourses.
He had detailed notes of his lectures turned into reviewed transcripts because he evidently went into his lectures with mere outlines (troped by his detailed tables of contents in the published versions) and thought “on his feet” (proving manifoldly that thinking is not re-presentation, a keynote of What Is Called Thinking?). The lectures are Heidegger thinking (usually; also, of course, he presented finely honed texts). The published transcripts—the textual canvases—are like realistic paintings of events (unable, in that era, to be photo-realistic, i.e., be videos—which anyway would have denied him the advantage of editing impromptu formulations—common in re-issued essays during his life, showing as footnoted marginalia to non-impromptu formulations). A formulation that is apt one year becomes inapt another year. (For example: ‘greatness’ was a pejorative term for Heidegger in the 1930s [like we understand ‘gross’ when disparaging something gargantuan]—shown commonly in his notebooks of that period—which readers in the 1950s might easily not recognize as negative in 1935’s Introduction to Metaphysics, thus being cause for adding a phrase before publication of the course, c1953.)
His lectures after circa 1940 bear in mind implicitly (for him) the unpublished major work to which he’d devoted himself, especially Contributions to Philosophy: from enowning (which is his actual “magnum opus,” not Being and Time, which “went too far too soon,” he wrote to Rudolf Bultmann, 1929). So, the lectures are implicitly alluding to stances from unpublished work, probably (and published work). The lecture transcripts are discursive dramas, worthy of enstantial, rhetorical analysis.
In particular, What Is Called Thinking? is a demonstration of philosophical teaching, not just a presentation about his view of the history of philosophy which happens to be very enlightening about Heidegger’s views.
Paradoxically, Heidegger avoided claiming that there was any such thing as “Heideggerian philosophy.” He taught thinking. He has even referred to “Heidegger” when he has talked about his work (letter to Wm. J. Richardson, 1962, if I recall correctly), speaking as dramatis personae.
Heidegger teaching is Martin being “Heidegger.” As Rector of Freiburg University, we see “Heidegger” playing rector. Arendt’s proverbial “rumor of the hidden king” was that a dramatist was in the room all the time. He was a charismatic exemplar of discursive performance art.
• next—> Working toward the work that bases the work of teaching