A topical essay defines, describes and delineates a topic. It does so with specific reference to the project and thesis. Simple as that. For example, in the Peter of Blois example, possible topics to deal with are:
Medieval Letter Collections (believe it or not, a very popular genre then -- everyone read them in school and out!);
Topics arise from many parts of the project, and very often from connecting literature review issues directly to your thesis and evidence. So comparing Eileen Power's 'Pit & Pedestal' idea versus LeClercq's biblical equality theory of gender can bring out some interesting medieval topics and sub-topics like mysogyny, patronizing (in the sense of paying for good work and in patting people on the head), biblical studies on gender (an ambiguous study itself), medieval power and influence, medieval marriage -- law, custom, social mores, church authority and its influence (or lack of...).
The following debate is interesting. Resolved: Topics or Context provide the greatest significance to historical inquiry. Let's say that some person (let's call her Jane) killed her lover (let's call him John) in mid-twentieth century Europe. The weapon is unimportant: supply your own -- either a gun, or she simply left him and it soooo broke his heart that he contracted pnumonia and passed away. Historical significance? None. A project here for the historian? Hardly. Let's say John, or Jane, was in politics. Or science. Or was a writer. That context might get the event some attention depending on how important either Jane or John was. A small-city mayor killed by a lover might make for local gossip for a year, while if Eva Braun killed her lover Adolf Hitler, .... well! If Eva did so, imagine all the topical essays that would be necessary to establish and explore explanations for the causes, course and myriad results of Eva's deed! It boggles the mind.
Contextual background (topical essays) can add to the thesis. Topical discussions can create contrasts to make the thesis stand out more prominently (Peter of Blois' lack of virtue, integrity, strength -- he wrote against Eleanor when King Henry II demanded it, then Peter dropped the letter from the collection and hid it away in order to work FOR Eleanor! -- contrasts strongly with the Renaissance/virtue context) Sometimes, context can succeed in doing both at once -- add background to make a natural setting for the thesis, and still put the thesis in high relief due to certain contrasts. Peter's weakness before royalty seems pitiable (versus integrity of a successful writer) yet is representative of his day AND our own (similarity). Consider, for example: Contrasting context? Natural setting context?
So far, I have resolved/argued that the 'hook' intro with the thesis/proposal is most important part of the project, and so it is. Also the Lit Review establishes an intellectual context without which the project flounders -- so very important is the Lit Review. Of course, Primary Source Evidence makes your case and so evidence is crucial. Now, the context is also of utmost importance! So what's not important? Exactly! If it is not important, it does not belong. Also important is style of writing, proper citation of sources, pertinent issues, debates presented well, interpretation and argument that examines opposing sides, insight into primary and secondary sources, arrangement, order, critique, conclusions..... if it is important, then it is not boring. And that's an important plus!
On to some specifics....
