Both Uses of

presume
in
The Narrative of the Life of Frederick Douglass

He is indeed presumptuous, and getting above himself; and nothing less than a flogging will do for him.†
Chpt 10 *

presumptuous = exercising privileges to which one is not entitled

He was generally called Captain Anthony—a title which, I presume, he acquired by sailing a craft on the Chesapeake Bay.†
Chpt 1

Definitions:

(1) (presume as in: presumption of innocence)
to think of something as true or likely, even though it is not known with certainty

Something can be presumed because it seems reasonable or because there is a rule or law demanding such an assumption. For example, in the United States someone charged with a crime is presumed by law to be innocent unless they are proven guilty at a trial.
(2) (presumptuous as in: she is presumptuous)
exercising privileges to which one is not entitled -- such as being too familiar or too bossy
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus