***** NOT A TEACHER *****
Good morning, Sumon:
(1) "Town and country" is a set phrase. It is not idiomatic (the way native speakers use the language) to use articles.
(2) I found this explanation (Google eBooks) from the November 2, 1861, issue of The Saturday Review of Politics:
"England, in times past, used to be divided into Town and Country [hills, fields]."
(3) The magazine explains that the old phrase, Town and Country, gives the capital [London] its pre-eminence [first place in the phrase].
(4) Here is another set phrase that I think that you would like to know: town and gown.
(a) "Town" refers to the residents of the town/city.
(b) "Gown" refers to the students and teachers of a nearby college.
(a) In the "old" days, college students wore gowns (something like a long robe).
(c) Many years ago (not today, of course) there was much unfriendly behavior between town and gown. (My note: maybe some of the town residents were envious of the college students; maybe some of the college students were not respectful of the town residents.)
(5) Therefore, your sentence seems to have a meaning something like this: Mr. Addison is trying to have the city residents and the country residents respect each other. I do not know which "Addison" your sentence refers to. If it is the famous Joseph Addison (died in 1719), then I assume that "town" refers to London. If you use this phrase today, I guess that it just refers to the relations between city and non-city residents.
HAVE A NICE DAY!
Student or Learner