There's one theoretical concept I feel I need to explain briefly in the literature review portion of my MA thesis, but it's very slightly tangential and I don't want to spend more than a paragraph on it. A textbook provides the most all-encompassing, thumbnail sketch of this concept, which would allow me to explain it while citing a single source rather than three or four journal articles.
Would it be déclassé to use a textbook as a reference in a MA thesis for this purpose?