 Early theorists who considered sense data to be mind-independent typically thought of them as persisting through time. Russell, in early sense-data writings (1912: ch. 1), viewed such data as existing apart from the mind as a special kind of thing (neither mental nor physical), which was commonly designated as a tertium quid or “third thing”, in addition to objects (such as a physical table) and the perceiver’s mental states. Such intermediary third things might be epistemically given only in the act of sensing them, but they would not depend for their existence on that act. This led to the notion of unsensed sense data (e.g., mind-independent patches of color), which were sometimes called “sensibilia” to indicate that they could be sensed if someone were at the right location, but that they existed in any case (Russell 1914b: sec. 3). In the second half of the twentieth century, when sense data came to be viewed mainly as mind-dependent, they were considered to be mental objects or contents of which we are directly aware. Accordingly, the white shape of the coaster-shaped patch would be a property of the mental object that is experienced, which was taken to mean that the mental state itself would have among its properties a white and roundish patch of color (Jackson 1977: chs. 4–5).