disquisition

noun

1. A methodical inquiry or investigation.

   “Near-synonym: inquisition”

   “Upon the subject of leases, as I wish to avoid all disquisitions which concern the kingdom at large, as much as the county of Lincoln in particular, it will be necessary only to remark, that great as have been improvements in it, I have not the least doubt they would have been much greater and more rapid, had the custom of granting leases been as common here as it is in Norfolk or Suffolk.”

   “..."What a feeling of security," continued he, "is flung round the uncertainty of love, by the calm and gentle images with which it is here invested!—" But their disquisition was interrupted by Lord Avonleigh, who came to announce that a deputation from Southampton waited without, full of eloquence and loyalty.”

   “The usual accusation against [Robert] Browning is that he was consumed with logic; that he thought all subjects to be the proper pabulum of intellectual disquisition; […]”

2. A lengthy, formal discourse that analyses or explains some topic; (loosely) a dissertation or treatise.

   “Upon this account political diſquiſitions, if juſt, and reasonable, and practicable, are of all the works of ſpeculation the most uſeful.”

   “It is only by considering the distance to which large quantities of these commodities are carried, […] that we can form any idea of the magnitude of the trade with India by land, and are led to perceive, that in a Disquisition concerning the various modes of conducting this commerce, it is well entitled to the attention which I have bestowed in endeavouring to trace it.”

   “The parts of this piece are ſo intimately connected, that any ſingle portion will appear with great diſadvantage in a detached ſtate: but we muſt give the critical reader a taſte of this elegant and maſterly diſquiſition.”

   “As these disquisitions were not originally intended for the public eye, the writer, several years ago, was induced to limit an impression of them to a small number of copies, that he might have the pleasure of placing them in the hands of a learned few, for whom he entertained a particular affection or respect, and whom he knew to be conversant with, or interested in, the subject of his enquiry.”

   “Though the work pretends to no more than the elementary or institutionary character, some of the disquisitions do honor to both the author's ingenuity and his learning.”