Boredom also plays a role in existentialist thought. Søren Kierkegaard and Friedrich Nietzsche were two of the first philosophers considered fundamental to the existentialist movement. Like Pascal, they were interested in people's quiet struggle with the apparent meaninglessness of life and the use of diversion to escape from boredom. Kierkegaard's Either/Or describes the rotation method, a method used by higher level aesthetes in order to avoid boredom. The method is an essential hedonistic aspect of the aesthetic way of life. For the aesthete, one constantly changes what one is doing in order to maximize the enjoyment and pleasure derived from each activity.
Different scholars use different definitions of boredom, which complicates research.[9] Boredom has been defined by Cynthia D. Fisher in terms of its main central psychological processes: "an unpleasant, transient affective state in which the individual feels a pervasive lack of interest and difficulty concentrating on the current activity."[10] Mark Leary et al. describe boredom as "an affective experience associated with cognitive attentional processes."[11] In positive psychology, boredom is described as a response to a moderate challenge for which the subject has more than enough skill.[12][full citation needed]
When the antiproton was discovered … it sent a wave of ennui through the physics community. Not that its discovery was unimportant, but on the basis of Dirac's theory, everybody expected it. — Roger G. Newton, The Truth of Science, 1997 Chauncey and I were keen enough about our aesthetic solution to the ennui of war to try to proselytize others. He organized discussion groups with the crew; I took volunteers to visit landmarks … — Louis Auchincloss, "Atlantic War," in Authors at Sea, ed. Robert Shenk,  1997 The attendant outside was standing on tennis balls, exercising the soles of her feet, her body swaying back and forth with the ennui of jelly. — Edna O'Brien, New Yorker, 17 June 1991 Thus the days of life are consumed, one by one, without an object beyond the present moment; ever flying from the ennui of that, yet carrying it with us … — Thomas Jefferson, in a letter dated 7 Feb. 1787 Thomas Jefferson: Writings,  1984 the kind of ennui that comes from having too much time on one's hands and too little will to find something productive to do