Answer and Explanation:
This is an excerpt from the novel "The Awakening", by author Kate Chopin.
Diction refers to an author's choice of words, particularly for clarity, effectiveness, and precision. Chopin's diction in the excerpt conveys the idea that the Doctor is an experienced man who values solitude. He is characterized as more of an introvert, someone who truly craves some time alone, some quietness:
"He was sorry he had accepted Pontellier's invitation. He was growing old, and beginning to need rest and an imperturbed spirit." - Impertubed means calm, quiet.
Also, the Doctor is knowledgeable when it comes to human nature, so he can predict what others want from him:
" He knew his fellow-creatures better than most men; knew that inner life which so seldom unfolds itself to unanointed eyes. [...] He did not want the secrets of other lives thrust upon him." - The highlighted words indicate the Doctor's experience has allowed him to get know people perhaps too well, to the point of seeing beyond what others see.