What's the difference between disquisition and disquisitory?

Disquisition

Definition:

(n.) A formal or systematic inquiry into, or discussion of, any subject; a full examination or investigation of a matter, with the arguments and facts bearing upon it; elaborate essay; dissertation.

Example Sentences:

(1) The idea of necessary connection, he says , "is every moment necessary for us to treat in all our disquisitions."
(2) In 1964, Ronald Reagan warned of the dangers of ceding our freedom to a little intellectual elite in a far-distant Capitol who think they can plan our lives for us better than we can plan our lives for ourselves,” he said, before a long disquisition about his domestic policy preferences for lower taxes, an end to deficit spending and more.
(3) In one of the epigraphs to the poem "Namely", a bristlingly humorous disquisition on his own unusual surname, he quotes Angus Calder, in Scotland on Sunday: "Few people thought Mick Imlah , who teaches at Oxford, was a 'Scottish poet'."
(4) So why not just let it all rip and: have fun with that, guys.” (Criticism of the Wharton essay rounded on Franzen’s observation that Wharton “wasn’t pretty”, something he suggested, not unreasonably, fed into her fictional disquisitions on the complicated currency of female beauty.)
(5) Five years ago, when YouTube started out, it was assumed to be where you went to look at cats that looked like Hitler, or people falling off skateboards, but TED Talks, with its short disquisitions on everything from neuroscience to creativity, has just celebrated 500m views on the site.
(6) The mainstream media adroitly handled, Trump began his disquisition on the subject dearest to his heart: his own success.
(7) As Kavanagh delivers an entertaining disquisition to the roomful of dedicated souls who have braved the wintry chill, one could be forgiven for thinking this was another example of the phenomenon that many argue contributed to the loss of the independence referendum: yes supporters talking to themselves.
(8) Her references to 17th-century disquisitions on falconry sit surprisingly easily in her memoir.