Editing Parmenides (section)

==== B9: Day and Night ====
Fragment 9 mentions again what was described in the final part of Fragment 8 as what mortals have conceived as the dual foundation of the world of appearance: the opposing principles "light" and "night", and says that everything is full of these opposites, and that nothing belongs exclusively to one of the two. In Fragment 9, Parmenides goes a step further, and states that the entire sensible realm can be reduced to manifestations of this pair of opposites, night and light ({{langx|grs|φάος}}, v.1), and that both penetrate the whole of reality equally.{{sfn|Kirk|Raven|Schofield|1982}} These forms can be considered to head a list of opposites, which serve as qualities to sensible things.{{sfn|Guthrie|1979|p=72}}

The idea of grouping under the fundamental opposite pair all the attributes of it has its parallel in the [[table of opposites]] of [[Pythagoras]].<ref>(58 B 4–5 = ''Met''. 986a23)</ref> Of course, in the Parmenidean table, oppositions that are not sensible must be excluded.{{sfn|Guthrie|1979|p=90}} For Simplicius,<ref>''Physics'' 38, 18–28</ref> it was clear that assigning fire the attribute of agent, which [[Alexander of Aphrodisias]] had done,<ref>''Commentary on Aristotle's Meteorology'', 31, 7 = A 7</ref> was a mistake. The reliability of all such evidence dependent on Aristotle is now highly doubted,<ref>Cherniss, ''Aristotle's Criticism of Presocratic Philosophy, 1935, p. 48, no. 192.''</ref> even when they reflect previous cosmogonic beliefs and it is not too risky to consider fire as active and earth as passive.{{sfn|Guthrie|1979|p=72}}

The fact that the goddess indicates (v.3-4) that everything is full of both night and light "equally" (ἴσων ἀμφοτέρων, ''ísōn amphotérōn'') is ambiguous; it could either mean "of equal rank," which would agree with Aristotle's interpretation, according to which one form "is" and the other "is not,"<ref>(''Met. 986b31'')</ref>{{sfn|Kirk|Raven|Schofield|1982}}<ref>Fränkel, ''Wege und Formen Frühgriechischen Denkens'', pp. 180–181.</ref><ref>Coxon, The Philosophy of Parmenides, p. 141</ref> or it could refer to an equality in quantity or extension, which would parallel a Pythagorean expression<ref>quoted by Diogenes Laertius, in ''Lives'' VIII, 26</ref> where in the cosmos, light and darkness are posited to equally cover (ἰσόμοιρα) the earth.{{sfn|Guthrie|1979|p=72}}