"You may be the fastest man alive, Allen. I'm the fastest mind."
Clifford DeVoe to Barry Allen
"Therefore I Am" is the seventh episode of the fourth season of The Flash, and the seventy-sixth episode overall. It aired on November 21, 2017.


Barry comes face to face with DeVoe. DeVoe's past is revealed through flashbacks. Meanwhile, Iris puts the final touches on the wedding, which is a week away.[src]



Guest Star


  • Paul Batten as Dr. Ortiz
  • Rob Compton as Police Officer #1
  • Tiffani Timms as Reporter #1


  • Yu Matsushita as Asako




  • The title is a reference to the philosophical proposition "I think, therefore I am", originally known in Latin as "Cogito ergo sum".
  • Marlize asks Clifford if he's seen a video of a Husky singing the Madonna song "Like a Virgin".
  • Cisco asks Barry if he's seen "Zatoichi the blind swordsman", a franchise of films and a TV series featuring the eponymous character.
  • At the press meeting held by Dr. "Wells" (secretly Eobard Thawne) at the turning on of the particle accelerator, he noted that Barry was present, along with Clifford and Marlize DeVoe. Thawne was excited at this and even remarked that he was a fan of DeVoe's "work", wishing him "good luck" for the future. Since Thawne was from the future, he likely knew DeVoe would one day become The Thinker, an enemy to the Flash.
  • Thawne's reappearance as "Harrison Wells" in this episode can be considered foreshadowing, as he returns in the crossover event Crisis on Earth-X with Harrison Wells' face, with his most prominent callback of being "Harrison Wells" in Part 3, which is the next episode, "Crisis on Earth-X, Part 3".
  • Similar to the comics, Clifford DeVoe obtains his high levels of intellect through his creation, "the Thinking Cap", which he even names the same. Also like in the comics, the Thinking Cap's use has detrimental effects on the rest of his body, though instead of a slow cancer like in the comics, it is a fast-acting paralysis.
  • The press conference scene from "Pilot" is shown again, making this the third time the scene is shown, after "Pilot" and "Things You Can't Outrun". However, most of the shots with "Wells" were refilmed for this episode, and the scene continues on after Barry and Iris run after the thief.
  • In the flashbacks, DeVoe reveals that 2,600 people were affected by the dark matter of the particle accelerator explosion.
  • Barry tells Iris that his "Spidey sense is tingling", referencing the Marvel superhero Spider-Man and his powers.
  • When Wally returns to Central City, he talks about fighting a giant starfish from outer space. This is a reference to the Justice League villain Starro.
  • This is the second episode in which Barry stays in his civilian persona and doesn't appear as the Flash, the first being "Girls Night Out".
  • This is the last episode of The Flash to credit Keiynan Lonsdale as a series regular, in addition to being credited in the main cast bill, as he became as a series regular in DC's Legends of Tomorrow (starting in the episode "The Curse of the Earth Totem").
  • Ralph Dibny only appears in the second sneak peek, which ended up being a deleted scene from the episode.


  • The date of the particle accelerator explosion is said to have occurred on January 7, 2014. However, it was previously stated by Felicity Smoak in "Episode 4" of the animated series Vixen and Cisco Ramon in the Arrow Season 3 episode "Broken Arrow" that the particle accelerator exploded on December 11, 2013.
  • When listing DeVoe's "charitable qualities", Harry mentioned that he volunteers at an orphanage. Orphanages in America had been completely replaced by the foster care system in the United States by the early 1970s.


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