Complex sentence: Although written quickly, and though Heidegger never completed the project outlined in the introduction, it remains his most important work and has profoundly influenced 20th-century philosophy, particularly existentialism, hermeneutics and deconstruction.
Split into simpler sentences: Although written quickly, and though Heidegger did not complete the project outlined in the introduction, it remains his most important work. It has profoundly influenced 20th-century philosophy, particularly existentialism, hermeneutics and deconstruction.