  If this objection is really concerned with perceptions strictly so called, then it obviously fails. Protagoras just accepts this supposedly absurd consequence; and apparently he is right to do so. If we consider animals and humans just as perceivers, there is no automatic reason to prefer human perceptions. Many animal perceptions are superior to human perceptions (dogs’ hearing, hawks’ eyesight, dolphins’ echolocatory ability, most mammals’ sense of smell, etc.), and the Greeks knew it, cf. Homer’s commonplace remarks about “far-sighted eagles”, or indeed Aristotle, in the Eudemian Ethics, 1231a5–6. The objection works much better rephrased as an objection about judgements about perceptions, rather than about perceptions strictly so called. Humans are no more and no less perceivers than pigs, baboons, or tadpoles. But they are different in their powers of judgement about perceptions.  