 One major criticism with Primitivism concerns whether the arguments for it depends on a questionable form of the doctrine of Revelation. (See Byrne &amp; Hilbert 2007a, for an expression of this criticism, among a set of other criticisms.) In response, many authors argue that the form of Revelation set out by Johnston is too strong, and there is a more moderate form of the doctrine that is more plausible (see J. Campbell 2005; Gert 2008; Allen 2011). It is worth noting that while Johnston and others cite Bertrand Russell and Galen Strawson as advocates of the doctrine, these two authors actually say very different things, in the quotes given to illustrate the doctrine. Russell, for example, places stress on the perceiver being acquainted with instances of color. The suggestion implicit in modest versions of the doctrine is that the appeal to Revelation needs little more than that.