Anxiety
The philosopher Søren Kierkegaard, in "The Concept of Anxiety" (1844), described anxiety or dread associated with the "dizziness of freedom" and suggested the possibility for positive resolution of anxiety through the self-conscious exercise of responsibility and choosing. In "Art and Artist" (1932), the psychologist Otto Rank wrote that the psychological trauma of birth was the pre-eminent human symbol of existential anxiety and encompasses the creative person's simultaneous fear of – and desire for – separation, individuation, and differentiation.
Barrington Moore Jr.
In 1965, Moore, Herbert Marcuse, and Robert Paul Wolff each authored an essay on the concept of tolerance and the three essays were collected in the book "A Critique of Pure Tolerance". The title was a play on the title of Immanuel Kant's book "Critique of Pure Reason". In the book Moore argues that academic research and society in general should adopt a strictly scientific and secular outlook and approach theories and conjectures with empirical verification.