Known as the father of existentialism, Søren Kierkegaard (1813-55) was an unconventional Danish religious and literary figure who promoted a severe and radically irrational notion of faith. His most famous notion is that of a “leap” of faith. In Fear and Trembling, he opposed faith to ethics in very strong terms, discussing at length the biblical story of God’s command to Abraham to sacrifice his son, and unequivocally taking the side of sheer obedience to divine command over all ethical considerations. This kind of fideism is pretty much anathema to me (see Rational Faith; Theology; Euthyphro).
Kierkegaard originated many completely undeserved negative stereotypes of Hegel. Even during the time I was much engaged with the French anti-Hegelians, reading Kierkegaard’s attacks always made me want to defend Hegel.