Husserl received from Martin Heidegger a copy of his Kant and the Problem of Metaphysics in the summer of 1929 not long before Husserl had determined to reread Heidegger's writings in order to arrive at a definitive position on Heidegger's philosophy. With this in view, Husserl reread and made extensive marginal comments in Being and Time and Kant and the Problem of Metaphysics. This essay by the translator of the remarks in KPM offers some historical background and comment on the importance of the remarks in KPM and attempts to describe Husserl's counterposition to Heidegger on six issues that divided the two major twentieth century philosophers.