In Mary Shelley's Frankenstein, what are disquisitions?

A disquisition is a formal discussion of a subject that often takes place in the form of writing.

In Frankenstein, the Monster reads Goethe's Sorrows of Werter — a novel consisting of letters written by a very sensitive and steadfast youth who kills himself as a way to end a love triangle. The Monster understands the moral vacuum in which young Werter lives; relates to Goethe's themes of solitude and alienation; and is mesmerized by Werter's thoughts about suicide:

But I thought Werter himself a more divine being than I had ever beheld or imagined; his character contained no pretension, but it sank deep. The disquisitions upon death and suicide were calculated to fill me with wonder.