 First, Peterson and Seligman are explicit that they do not think this classification is exhaustive, and are open to additions or deletions (2004: 13; see also Peterson and Park 2009: 27). Second, they acknowledge that “In some cases, the classification of a given strength under a core virtue can be debated” (Peterson and Seligman 2004: 28, 31). And finally, they “regard these strengths as ubiquitously recognized and valued, although a given individual will rarely, if ever, display all of them” (2004: 13).