• The preface speaks of Kant’s aims with reference to his predecessors, especially Hume. You should think where you have read in Hume the views Kant ascribes to him. The first three of the “opponents” of Hume that Kant mentions on p. 4—of whom Thomas Reid was by far the most important—are usually referred to as “common sense” philosophers. (Kant probably groups the four because Priestley had published a book critical of the other three. Although Priestley was not himself an important philosopher, he was an important scientist; among other things, he is one of the discoverers of oxygen.)

• In the preface, Kant speaks of being awakened from “dogmatic slumber” by Hume (p. 5). One possibility for the nature of this awakening is found in the letter to Herz printed at the end of the Ellington translation of the Prolegomena: look for Kant’s discussion, beginning near the bottom of p. 117, of something he noticed. This leads him to describe a problem regarding the source of our ideas (you can regard ‘representation’ as a rough synonym of ‘idea’) which he eventually says that he has solved (p. 120), though he doesn’t describe his solution. It apparently took him some time to work out this solution to his satisfaction. Although he says he expects to publish a book based on it in 3 months, the Critique of Pure Reason did not appear for almost 10 years.