 The only point where Aristotle’s representation of Parmenides in Metaphysics 1.5 appears to differ from the major treatment in Physics 1.2–3 is in following up this summary with the qualification that, being compelled to go with the phenomena, and supposing that what is is one with respect to the account (sc. of its essence) but plural with respect to perception, he posited a duality of principles as the basis for his account of the phenomena (986b27–34, reading to on hen men at 986b31, as per Alexander of Aphrodisias’s paraphrase). This is only a superficial difference, given how at Physics 1.5.188a19–22 Aristotle points to the Parmenidean duality of principles to support his thesis that all his predecessors had made the opposites principles, including those who maintained that everything is one and unchanging. Nonetheless, the representation of Parmenides’ position in Metaphysics 1.5, according to which what is is one with respect to the account of its essence but plural with respect to perception, is more indulgent than the reconstruction of Parmenides’ reasoning in Physics 1.3 in that it allows for a differentiated aspect of what is. By allowing that what is may be differentiated with respect to its phenomenal qualities, Aristotle seems to have recognized at some level the mistake in assuming that Parmenides’ failure to distinguish explicitly among the senses of “being” entails that he could only have employed the term in one sense.