lization. Thus the Egyptians saw water and the sun as symbols of life and thought of time as a series of natural cycles. This orderly pattern was at constant risk of disruption: unusually low floods resulted in famine, and high floods destroyed crops and buildings. The hospitable Nile valley was surrounded by harsh desert, populated by peoples the Egyptians regarded as uncivilized enemies of order. For these reasons, the Egyptians saw their land as an isolated place of stability, or maat, surrounded and endangered by chaos. These themes—order, chaos, and renewal—appear repeatedly in Egyptian religious thought. Another possible source for mythology is ritual. Many rituals make reference to myths and are sometimes based directly on them. But it is difficult to determine whether a culture's myths developed before rituals or vice versa. Questions about this relationship between myth and ritual have spawned much discussion among Egyptologists and scholars of comparative religion in general. In ancient Egypt, the earliest evidence of religious practices predates written myths. Rituals early in Egyptian history included only a few motifs from myth. For these reasons, some scholars have argued that, in Egypt, rituals emerged before myths. But because the early evidence is so sparse, the question may never be resolved for certain. In private rituals, which are often called "magical", the myth and the ritual are particularly closely tied. Many of the myth-like stories that appear in the rituals' texts are not found in other sources. Even the widespread motif of the goddess Isis rescuing her poisoned son Horus appears only in this type of text. The Egyptologist David Frankfurter argues that these rituals adapt basic mythic traditions to fit the specific ritual, creating elaborate new stories (called historiolas) based on myth. In contrast, J. F. Borghouts says of magical texts that there is "not a shred of evidence that a specific kind of 'unorthodox' mythology was coined... for this ge