On the standard view, a demonstrative concept is something like an indexical (see the entry on indexicals).
The actual referent of a token demonstrative concept is taken to constitute or be essential to its content, but unlike the indexical concepts just discussed, the reference of a demonstrative is not fixed automatically by the speaker's identity, location and time; something else is needed to fix the reference.
But since the recognitional demonstrative concepts the conceptualist appeals to do depend on such memory capacities (according to the re-identification condition), it cannot be the case that our having such demonstrative concepts is necessary for our enjoying fine grained perceptual discriminations.
However, it is again a matter of controversy whether demonstrative concepts are limited in this way.
(He notes (2003: 227) that demonstratives are naturally used to express direct phenomenal concepts (e.g., "I am experiencing this quality"), and that there may be a sense in which a direct phenomenal concept is a "demonstrative" concept, but he avoids such a label at least in part because of the danger of confusing direct phenomenal concepts with demonstrative ones as usually understood).
As such, it must be the case that such demonstrative concepts as are arguably involved in the content of perception are retained long enough for the possibility of their remobilization they cannot be reserved only for the particular instance in which the sample is perceived.
According to Peacocke, one role of scenario content is to make it possible for the subject to form demonstrative concepts, such as ones that might naturally be expressed by that figure, that color, that shape, where the figure, color or shape picked out by the concept is one that is represented in experience.
Two potential challenges to the appeal to demonstrative concepts have been highlighted.
Then the subject cannot have an appropriate demonstrative concept, as there is nothing to fix the reference of that concept.
The demonstrative concepts I possess are a function of my demonstrative capacities and part of what explains my having a given demonstrative capacity is my having certain associated experiences; the experience must be prior to the possession of the demonstrative concept if the former is to explain the latter (Heck 2000).
As McDowell says, the capacity for employing demonstrative concepts in perception is a recognitional capacity (McDowell 1994a p. 57, Brewer 1999 also holds that a conceptual capacity must be available in the absence of the sample to which it was initially applied).
