Masseter muscle is partly concealed, anteriorly, by the superficial portion. Posteriorly, it is covered by the parotid gland. Along with the other three muscles of mastication (temporalis, medial pterygoid, and lateral pterygoid), the masseter is innervated by the anterior division of the mandibular division (V3) of the trigeminal nerve. The innervation pathway is: gyrus precentralis > genu capsula interna > nucleus motorius nervi trigemini > nervus trigeminus > nervus mandibularis > musculus masseter. The action of the muscle during bilateral contraction of the entire muscle is to elevate the mandible, raising the lower jaw. Elevation of the mandible occurs during the closing
What the Tortoise Said to Achilles to suggest that the moral of the dialogue is a particular case of a general lesson, to the effect that the proper "application" of rules governing a form of human activity cannot itself be summed up with a set of "further" rules, and so that "a form of human activity can never be summed up in a set of explicit precepts" (p. 53). Carroll's dialogue is apparently the first description of an obstacle to conventionalism about logical truth, later reworked in more sober philosophical terms by W.V.O. Quine. What the Tortoise Said to Achilles "What the Tortoise Said to Achilles",