- "I'm thinking."
- —Clifford DeVoe to his wife[src]
Clifford DeVoe, nicknamed The Thinker by Cisco Ramon is a history professor at Central City University, and secretly an extremely knowledgeable enemy of the Flash. Before he lived in Central City he lived in South Africa with Marlize DeVoe. He works alongside Marlize DeVoe, his assistant and wife.
Studies and teaching
Clifford DeVoe was raised in South Africa. When he grew up, he studied history and econometrics at the University of Johannesburg, Clifford first took a teaching position at the University of Oxford, specializing in the history of warfare and military strategy, focusing largely on the early Middle Ages. There he'd meet Marlize, and the two fell in love and eventually married. Circa 2006, while at Oxford, Clifford was a member of the debating society, debating the morality of Sun Tzu and the principles of Machiavelli. At that time, he also held a number of lectures in Central City University: on Japanese political fragmentation in the 15th century on June 13th; on the Menji Restoration of 1868 in September; on the Battle of Hakusukinoe in October. He would later accept an invitation to become a professor at CCU, moving to live in Central City, United States.
Birth of the Thinker
Clifford and Marlize, now living in Central City, worked on adapting to their new lives and saw progress for human development through the acceleration of mind, with Clifford thinking that his own genius was not enough to achieve their plan of "distributing knowledge" throughout society. Coincidentally, the couple followed the progresses of S.T.A.R. Labs under Dr. Harrison Wells, specifically his S.T.A.R. Labs particle accelerator project. Upon realizing that the particle accelerator would explode, the DeVoe family developed a machine to amplify DeVoe's intelligence by using the dark matter from the particle accelerator explosion to power his "Thinking Cap" device. While the experiment was a success, DeVoe began to suffer from degeneration in his body, slowly paralyzing him and causing him seizures and pain. With his body trying to maintain the vast intellect, the rest of his body was not receiving the energy it needs. Clifford's wife has thus built a machine that plugs into DeVoe's brain to slow down his deteriorating body.
In October 2017, DeVoe and Marlize had a samurai droid built to force the Flash to make his return to Central City, causing dark matter to spill out and transform a busload of 12 people into meta-humans. After the samurai robot was defeated, DeVoe used it to anonymously welcome the Flash back. After rebuilding another Samuroid in his hideout, DeVoe mused on how everything was going according to plan with the Flash's return and began to plan his next move.
Later, DeVoe got up early in the morning, researched all of Schubert's 600+ works and used this knowledge to finish his unfinished eighth symphony, playing it on a holographic piano. Marlize approached him, musing how she enjoyed the song as a child. DeVoe proceeded to ask her for an update on the meta-humans, to which she showed him she managed to locate Ramsey Deacon locked up at Iron Heights Prison. DeVoe then decided it was time to locate the others.
Shortly following, as DeVoe and his wife watched over an incarcerated Becky Sharpe, the latter remarked on how Team Flash had found her significantly quicker than they'd anticipated, suggesting they were smarter than they'd thought. DeVoe, however, was sure that he was smarter, revealing a live feed to S.T.A.R. Labs from the defect Samuroid head.
He tracked down a meta-human called "The Weeper" a week later and told him that he went through a lot of trouble in creating him and that he couldn't die until he completed the task he was created for.
When Marlize came to him, saying they needed to talk, he responded that it would end the only way it could which was his victory. She seemed confused and he said that they would have to take the conversation the long way. She then alerted DeVoe to the fact that Team Flash were closer to discovering his identity earlier than they had anticipated. He assured her that everything was fine as he had calculated every possible variable as well as all possible outcomes of their conversation and how it would end. When she asked how it would end, he repeated his earlier statement that it would all end with his victory. Not long following, they were visited by Joe West and Barry Allen, who asked to speak to Clifford, who appeared in simple clothes and in an electric wheelchair, away from his mechanized hovering chair.
DeVoe is a calculating and patient man, very much focused on his current objective all the time, not having much emotional reaction while doing so. He is very confident in his abilities. DeVoe's also possessed an ambitious nature even before his transformation, wishing to advance the human consciousness to instill change in humanity.
Powers and abilities
- "There is not a decimal, a fraction, an infinitesimal variable beyond my thought... beyond my mind!"
- —Clifford DeVoe[src]
- Meta-human physiology: After being struck by the S.T.A.R. Labs particle accelerator while wearing his "Thinking Cap", Clifford's already intelligent mind was enhanced to superhuman levels. However, when Caitlin Snow ran a DNA test if he was a Meta-human the results were negative.
- Accelerated Thinking: Clifford's powers greatly accelerate his brain activity, allowing him to find answers to various questions at a speed beyond normal human levels, even faster than Barry.
- Superhuman Intelligence: With his brain energized from the particle accelerator explosion, Clifford's cognitive abilities are some of the greatest in the multiverse. With his enhanced intelligence, Clifford feels that he knows the answer to almost any problem known to man and has solved many mysteries with his intelligence including: Riemann's hypothesis, one of Hilbert's problems, Jack the Ripper's identity, and many others.
- Genius-level intellect: Even before his mutation, Professor DeVoe was a mastermind scientist, specializing in many fields of study, most notably history.
- Adept Engineer: Because of his intelligence, Clifford was able to create the schematics of the designs of the Samurai robots and the "Thinking Cap".
- Expert chess player: Clifford is masterful in chess, playing against advanced computer simulations.
- Expert Historian: A professor of Medieval history, Clifford is a brilliant historian with the Feudal Era of Japan being a particular favorite of his.
- Master Tactician: Clifford's intelligence makes him a near-flawless strategist with his feats pushing Team Flash into bringing Barry back from the Speed Force while simultaneously sending a bus in a precise location of where Barry would come out at the exact moments resulting in 12 individuals to become Meta-humans. Clifford's intelligence offers him frightening calculations allowing him to predict various scenarios of potential future problems such as an when Team Flash would discover his identity, an argument with his wife, and more.
- Mathematician: Despite specializing in human studies, Clifford was a great mathematician.
- Multilingual: Clifford has the ability to speak English, Japanese, French, Italian, Mandarin, and several other languages.
- Musical ability: Clifford is a skilled pianist, he was also able to finish Schubert's unfinished eighth symphony by extrapolating the remaining movements after he familiarized himself with the body of his other 600 works in a single morning.
- Body degeneration: While DeVoe's intellect was boosted to super-human levels from the explosion, his body began to deteriorate due to the massive amount of energy his brain needs to function. This illness is an advanced form of ALS, causing his nerves and muscles to start deteriorating, which resulted in DeVoe's paralysis and can eventually be fatal. His hovering chair is designed to stall this fatal deterioration, though it too will eventually fail to keep DeVoe from dying.
- Cerebral inhibitor: According to Savitar, Barry will use a version of the device to defeat DeVoe at some point in the future. 
- Exposed brain: For his cybernetics to work, Clifford's brain has to be exposed, with the upper half of his skull removed.
- Hovering chair: DeVoe uses a mechanical chair, connected with wires to his hideout's computer system. The chair is also able to hover in mid air and has offensive capabilities in form of blasters.
- Wheelchair: DeVoe uses a wheelchair when he is required to appear as a civilian in public.
- Thinking Cap In 2014, just before the S.T.A.R. Labs particle accelerator explosion Devoe designed the thinking cap to boost his own intelligence. He had his wide build it and he put it on his head during the explosion and it was struck by lightning, it is unknown what happened to the cap after that.
- Like Damien Darhk, DeVoe was first mentioned 2 times on the third season of his show, and became the main antagonist in the following season.
- During Therefore I Am, DeVoe admits to his wife that in his many predicted future scenarios, one of Cisco's supervillain names would have been The Teacher.
- The Thinker is the first main antagonist of The Flash who is not a speedster.
- Unlike the previous main antagonists of The Flash, DeVoe's identity as a villain was revealed to Team Flash very early in the season (on the seventh episode of the fourth season,""). The identities of the other villains were revealed only at the near end of the seasons:
- Reverse-Flash's identity was revealed on the nineteenth episode of the first season, "" (however, Team Flash suspected that he was Harrison Wells a few episodes before; he also revealed his identity to Cisco Ramon in an aborted timeline in the fifteenth episode "").
- Zoom's identity was revealed on the sixteenth episode of the second season, "".
- Savitar's identity was revealed to Barry on the twentieth episode of the third season, "" (However, he told the rest of the team only in the following episode, "").
Behind the scenes
- In the DC comics Clifford DeVoe was the first villain known as the Thinker, a genius inventor corrupted by Hunk Norvok and enemy of Jay Garrick, whose brain-boosting "Thinking Cap" invention went on to gain artificial intelligence and become an enemy of the Wally West Flash, using DeVoe's name after his demise, which was caused by the Cap's detrimental effects on his body over the years. Similarly, Devoe on the show struggles to keep his body healthy with his overclocked mind slowly killing him.