Abstract
Heraclitus is famous for affirming contradictions, though most readers do not regard the content of his fragments as contradictory. Examining fragments 1 and 50, this article argues that Heraclitus aims to assert a special class of contradictions, the intrinsic conflict between the content of any universal metaphysical claim and the assertion or reception of that claim. Such contradictions undermine the possibility of metaphysics as a science that knows all things. Second, the article argues that Heraclitus himself embraces this sort of contradiction by making it, as it were, the content of his Logos. Third, the article examines three other solutions to the problem that have been advanced, mostly tacitly, by other philosophers. The article concludes with some steps towards a different way of preserving the possibility of metaphysics.