 Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated the episode four stars out of five. The two wrote that "the episode sings when it reinvents the old and introduces the new." However, Shearman and Pearson criticized the bringing back of Gibson Praise, noting that "the return of Gibson Praise almost derails the episode altogether […] he only manages to make an episode that seemed as if it was giving The X-Files a bold new beginning feel like it's about to offer more of the same old stooge." Tom Kessenich, in his book Examinations wrote a moderately positive review of the episode. He noted, "In many ways,' Within ' reminded us why we tune into The X-Files every week. However, it also reminded us why the road ahead will be difficult. Fox Mulder may be gone, but he will never be forgotten. Or replaced."
