barbarians shall not go unrenowned, and, among other things, to set forth the reasons why they waged war on each other." This mode of explanation traces itself all the way back to Homer, who opened the Iliad by asking: Which of the immortals set these two at each other's throats? Zeus' son and Leto's, offended by the warlord. Agamemnon had dishonored Chryses, Apollo's priest, so the god struck the Greek camp with plague, and the soldiers were dying of it. Both Homer and Herodotus begin with a question of causality. In Homer's case, "who set these two at each other's throats?" In Herodotus's case, "Why did the Greeks and barbarians go to war with each other?" Herodotus's means of explanation does not necessarily posit a simple cause; rather, his explanations cover a host of potential causes and emotions. It is notable, however, that "the obligations of gratitude and revenge are the fundamental human motives for Herodotus, just as ... they are the primary stimulus to the generation of narrative itself." Some readers of Herodotus believe that his habit of tying events back to personal motives signifies an inability to see broader and more abstract reasons for action. Gould argues to the contrary that this is likely because Herodotus attempts to provide the rational reasons, as understood by his contemporaries, rather than providing more abstract reasons. Types of causality Herodotus attributes cause to both divine and human agents. These are not perceived as mutually exclusive, but rather mutually interconnected. This is true of Greek thinking in general, at least from Homer onward. Gould notes that invoking the supernatural in order to explain an event does not answer the question "why did this happen?" but rather "why did this happen to me?" By way of example, faulty craftsmanship is the human cause for a house collapsing. However, divine will is the reason that the house collapses at the particular moment when I am inside. It was the will of the gods that the house collapsed while a particular individual was within it, whereas it was the cause of man that the house had a weak structure and was prone to falling. Some authors, including Geoffrey de Ste-Croix and Mabel Lang, have argued that Fate, or the belief that "this is how it had to be," is Herodotus's ultimate understanding of causality. Herodotus's explanation that an event "was going to happen" maps well