Several conflicting hypotheses have been posited on the subject. He quoted philosophers who posited the same basic idea several centuries ago. Four principles are posited to underlie social stratification. Similar hypotheses have also been posited for the rise of food and other allergies. While ongoing disagreement about exact stages exists, many economists have posited the following general states. Saussure posited that no word is inherently meaningful. Two explanations for this phenomenon have been posited. This theory was originally posited by Abdel Omran in 1971. This principle is sometimes phrased as ("Plurality should not be posited without necessity"). Between 1935 and 1939, Greek archaeologist Spyridon Marinatos posited the Minoan eruption theory. Several explanations for this have been posited, most involving cataracts. Grotius posited that individual humans had natural rights. But when is a thing thus posited? While agricultural use has been posited, no clear evidence has been presented. He also posited tornado vortex structures and formative processes.