 Peter Sullivan has suggested a different way of imputing an identity theory to the Tractarian Wittgenstein (2005: 58–9). His idea is that Wittgenstein’s simple objects are to be identified with Fregean senses, and that in effect the Tractatus contains an identity theory along the lines of (7) or (10). Sullivan’s ground for treating Tractarian objects as senses is that, like bona fide Fregean senses, they are transparent: they cannot be grasped in different ways. An apparent difficulty with this view is that there is plausibly more to Fregean sense than just the property of transparency: after all, Russell also attached the property of transparency to his basic objects, but it has not been suggested that Russellian basic objects are really senses, and the suggestion would seem to have little going for it (partly, though not only, because Russell himself disavowed the whole idea of Fregean sense).The orthodox position, which will be presupposed here, is that the Tractarian Wittgenstein like Russell, finds no use for a level of Fregean sense, so that his semantical hierarchy consists exclusively of levels of language and reference, with nothing of a mediatory or similar nature located between these levels. (Wittgenstein does appeal to the concepts of sense and reference in the Tractatus, but it is generally agreed that they do not figure in a Fregean way, according to which both names and sentences, for example, have both sense and reference; for Wittgenstein, by contrast, sentences have sense but not reference, whereas names have reference but not sense.)