»Fear and Trembling

Today marks the Islamic holiday Eid al-Adha, the Festival of Sacrifice. When God commanded (or requested) that Abraham take Isaac on a trip over to the mountain, whereupon the head of the latter would be removed by the former as a sign of devotion to God -- well, Abraham snapped his heels together and dressed his only son in his Sunday best. He told his wife Sarah that he would return post-haste, but omitted that Isaac would not require round-trip busfare.
Soren Kierkegaard examines this parable in Fear And Trembling, and asks the reader to question the nature of ethics, and of good and evil: are these intrinsic to the cosmos, or determined by the orders of God? are ethics teleological, and this subject to order?
I have the Penguin Classics edition of this short work, and -- rare amongst my books -- I marked the inside cover with my name, and with the place and date of each time I have read it: Chicago, 1991; Pittsburgh, 1995; Park City, 2002; Fès, 2002 (wow: I bet I ate some great lamb on that trip!).
A similar parable occurs in Greek legend: Euripides makes use of it in his retelling of Agamemnon's sacrifice of Iphigenia, Iphigenia at Aulis; Plato examines the directives of ethics in Euthyphro, amongst other dialogues.