. . . . The dynamic of existence is determined, for Pascal, by the impossibility of a state of complete quiet or rest (repos). "Nothing is as unbearable for man as to be completely at rest, without passion, without business, without distraction, without application to something." In such a state of rest man becomes aware of "his nothingness, his foresakenness, his insufficiency, his dependence, his impotence, his emptiness."
Incontinently there springs from the depth of his soul "the ennui, the blackness, the tristesse , the chagrin, the spite, the despair." 1
What Pascal tries to describe by this array of terms denoting the facets of a fundamental mood is what is called in modern philosophy of existence since Kierkegaard the "anxiety of existence."
The intoxication of activity beclouds the reality of human existence; when passion subsides, the experience of a fundamental emptiness and metaphysical forlornness emerges unobscured; the anxiety of existence springs up urging to be assuaged; and the ordinary method of assuaging anxiety is the divertissement by new activity. . . . This anxiety of existence has no specific cause; if man felt safe in every respect, still the ennui would rise on its own account from the depth of the heart; the free-rising, causeless ennui is due to the constitution of man's existence (par l'état propre de sa complexion). 2