 Why do we misperceive our perceptions of persons or their parts as being perceptions of sense-data? Unlike the case of material objects, when we perceive something as a sense-datum, our perception itself (rather than a judgment we are led to by the perception) is mistaken. McTaggart hypothesizes that, if there is a single cause of this widespread error, it must be connected with the fact that we misperceive a C-series as an A-series. This hypothesis is somewhat supported by the fact that whenever we perceive some object, we always perceive that object as being in  time.[26] So the appearance of time is systematically connected with every appearance of something else, and is possibly responsible for radically distorting how that something else appears. 