"Spock, you are fully capable of deciding your own destiny. The question you face is: which path will you choose? This is something only you can decide."
Spock – full name generally considered unpronounceable to Humans – was a Human/Vulcan hybrid who served with Starfleet in the 23rd century. As an instructor at Starfleet Academy, he programmed the Kobayashi Maru scenario. From 2258, he was first officer under Christopher Pike and his successor, James T. Kirk, aboard the USS Enterprise. (Star Trek)
As a young boy, Spock was often the target of abuse from his schoolmates because of his Human ancestry. On one particular occasion in which three of his classmates accused his father of being a traitor for marrying "that Human whore," Spock lost emotional control and was so angered that he violently beat up the lead tormentor, exhibiting such rage that, despite their advantage in size and numbers, the other two made no attempt to help their friend. Previously, he had counted that the incident was the thirty-fifth time those particular schoolmates had attempted to elicit an emotional response from him. When he then spoke to his disappointed father about his mother, asking him why he had married a Human, Sarek coldly remarked that his decision to marry her was the logical choice, given that he was an ambassador of Vulcan to Earth.
After completing the advanced training which he began during childhood in the Vulcan Learning Center, Spock applied to both the Vulcan Science Academy and Starfleet Academy. He was also considering completing his training in the kolinahr – the Vulcan ritual of purging all vestigial emotions – and asked his mother whether she would think less of him for discarding emotion in that way. His mother simply remarked that she would always be proud of him, no matter what choices he made. He later was admitted to the Vulcan Science Academy, but declined the offer after the board remarked that his admission to the Academy was especially commendable considering his "disadvantage" of being half-Human.
Spock went on to attend Starfleet Academy, and would come to be known as one of its most distinguished graduates. By 2258, he had attained the rank of commander, and acted as an instructor at the Academy.
Spock was in charge of starship assignments for the cadets. He initially assigned Lieutenant Nyota Uhura to the USS Farragut, in spite of Uhura's stated desire to serve aboard the USS Enterprise, the new flagship. Commander Spock had served as Cadet Uhura's instructor and judged her performance to be consistently exemplary but, to avoid giving the appearance of favoritism, he assigned her to the Farragut instead. Uhura later confronted him about this choice, noting that she was more than qualified to serve aboard the Enterprise as confirmed by Spock on many occasions. After this conversation, she was assigned to the Enterprise by Spock.
Spock programmed the Kobayashi Maru scenario, the purposes of which were to allow cadets to experience fear in the face of death and, in confronting such fear, to enable them to develop skills necessary for command. When James T. Kirk was ultimately able to pass the test and defeat the scenario, Spock accused the cadet of inserting a subroutine into the program, changing the simulation to his favor, so he could win. At a hearing of the Academy board, Kirk asked for the right to confront Spock directly, and the two clashed over Kirk's actions.
The hearing was cut short by the receipt of a distress call from Vulcan, and Spock reported to the USS Enterprise as first officer under Captain Christopher Pike. En route to Vulcan, Spock once again clashed with Kirk, who had come aboard the Enterprise without authorization. Over Kirk's arguments that the distress call from Vulcan was the result of an attack by Romulans, Spock demanded that Kirk be removed from the bridge – but when Uhura vouched for the accuracy of a crucial element of Kirk's claims, Spock decided that Kirk was probably right, and as a result, Pike ordered the ship ready before dropping out of warp. Ultimately, arrival at Vulcan, which was under attack, proved that Kirk was correct, and contact was made with the Romulan vessel Narada, which was attacking the planet. When contact was established with the ship's captain, Nero, he appeared to know Spock, although Spock had never met the Romulan before. Pike, who was ordered to transport himself to the Narada, left Spock in charge as acting captain.
Following the disabling of the Narada's drill platform and revealing Nero's plans, Spock beamed to the surface to at least rescue the Vulcan Council, including his father and mother. As the survivors were about to be beamed aboard the Enterprise, the disintegrating surface of the planet collapsed beneath Spock's mother before the transport could be completed and she died. She was one of almost six billion killed with the loss of the planet.
Struggling with the loss of his world and the death of his mother, Spock received comfort from Uhura. After deciding to take the Enterprise to the Laurentian system to rendezvous with the rest of the fleet, and engaging in a furious debate with Kirk which led to him employing the Vulcan nerve pinch on the acting first officer, Spock ordered Kirk to be thrown off the ship, jettisoning him in an escape pod near Delta Vega.
With the Enterprise now at warp, Spock was surprised when Kirk and Montgomery Scott were able to beam aboard the ship, and demanded to know how they had been able to transport during warp. Kirk, who had by now met with a version of Spock who had traveled back in time with Nero, had also been told that in order to save Earth, he himself had to take over command of the Enterprise. The older Spock had asked Kirk to sufficiently provoke the younger Spock, in order to show everyone that he was too emotionally compromised to be in command. Kirk made several unsuccessful attempts to insult and cajole Spock, until finally a jibe about whether Spock had loved his late mother made the Vulcan snap, attacking Kirk and coming extremely close to killing him. He was only stopped by his father and, quickly realizing what had happened, he stepped down from command. Returning to the transporter room, Spock was comforted by the words of his father, who admitted that he actually had married Amanda because he loved her.
After a brief cool-down period, Spock returned to duty, accepting Kirk's command, and endorsed Pavel Chekov's plan to hide the Enterprise in Titan's atmosphere. He then volunteered to beam to the Narada, noting that the similarities between Romulan and Vulcan language and culture would help him in determining the location of Captain Pike and determine a way to destroy the vessel. Kirk, now in command, agreed, and accompanied Spock aboard the Narada. In the Enterprise transporter room, Spock and Uhura kissed. When told by Uhura that she would be monitoring their comm frequencies, Spock thanked "Nyota", revealing the first name Kirk had attempted unsuccessfully to learn ever since first meeting her three years prior.
After a brief phaser fight with the Romulan crew aboard the Narada, Spock was able to locate the the elder Spock's ship and Captain Pike. On board the Jellyfish, the computer recognized him as Ambassador Spock; when Kirk made an obviously sarcastic show of "surprise" and the computer stated that the ship had been built 129 years in the future, Spock realized exactly who Kirk had encountered on Delta Vega.
Attacking the Narada from the inside, Spock escaped into Earth's orbit, and was able to destroy the drill platform as it dug into San Francisco Bay. Ultimately, the black hole, with assistance from the Enterprise's weapons, consumed the Narada and Nero, who had refused humanitarian assistance. Spock, angered over the destruction of his world, took the non-logical path for once, telling Kirk that while it was logical to offer help, this time he didn't want to do it.
First officer of the Enterprise
Back on Earth, Spock finally met with his older counterpart, who explained to him that he had wanted to make sure that Spock and Kirk became friends and shared the kind of friendship he and the other Kirk from his timeline shared: something which would ultimately define them both and was a crucial aspect of their lives. Spock had planned to resign from Starfleet and help rebuild Vulcan society, but the elder counterpart urged him to remain with Starfleet and to also put aside logic once in a while and do what felt right. About to join the surviving Vulcans himself, the prime Spock chose not to offer his alternate self the traditional Vulcan salute, noting that it would have seemed self-serving; instead he wished him good luck.
With Kirk now in command of the Enterprise, Spock offered his services as First Officer, which Kirk gladly accepted.
Although it was kept as a secret  for the most part Spock and Uhura had a romantic relationship that has been established prior the start of their careers on board of the Enterprise. Since Spock was an instructor at the Starfleet Academy he met Uhura while she was one of his students and, possibly later, the Academy aide for his Advanced Phonology class . However, it is still unknown under which circumstances a relationship was formed between them and if she still was one of his students at the time. While on board of the Enterprise, Spock and Uhura maintained a formal professional relationship and the true nature of their feelings for one another was showed only in some rare occasions where the apparent adopted formality of their interactions while at work was replaced by hints of familiarity e.g., when Uhura openly confronted him about her getting assigned to the USS Farragut even though she was qualified to serve aboard the USS Enterprise to which Spock replied that his decision was just "an attempt to avoid the appearance of favoritism"; a concerned Uhura calling him by name and not by rank when he was about to beam himself to the Vulcan surface to rescue his parents and the Vulcan High Council: her being the only person to whom in the midst of a crisis he actually paused to explain what he was about to do and his reasons. However, the most explicit hint about them being connected beyond a professional partnership had been when Uhura comforted Spock after Vulcan had gotten destroyed by Nero and in the privacy of the turbolift he did take comfort from her. Later, their relationship was revealed to James Kirk and Scotty when they did witness Spock and Uhura kissing in the transporter room where Spock also called her by her first name "Nyota".
James T. Kirk
Spock and Kirk had a complicated and troubled relationship from the start. As an instructor at Starfleet Academy and the creator of the Kobayashi Maru scenario, Spock did not appreciate that Kirk had altered the program so he could beat it. In fact, he openly accused him of having cheated and as a result, Kirk had to answer before an inquiry board at the Academy for his actions. Kirk was subsequently suspended and only with the help of Doctor Leonard McCoy was he able to come on board the Enterprise. Kirk and Spock continued to clash with one another over vastly different view points and philosophies they held. Kirk was self-assured, overconfident and had an unconventional way of approaching matters, while Spock was highly disciplined, always honoring regulations and adhering to a strict code of conduct. Spock's lack of tolerance for Kirk's ways resulted in Spock just throwing Kirk off the ship altogether, the first opportunity he got. When Kirk later provoked him by referencing his mother, Amanda Grayson, Spock lost all control and was more than eager to hurt Kirk.
Spock's attitude toward Kirk softened, however, after his encounter with an alternate version of himself who advised both of them to set aside their momentary irritations, revealing that in his timeline, the two had shared a great friendship. After they worked side by side to save Earth and beat the Narada, Spock became Kirk's first officer aboard the Enterprise.
"I'm sorry. I'm sorry. I'm so sorry. What do you need? Tell me. Tell me."
"I need everyone to continue performing admirably."
- - Nyota Uhura and Spock, when Uhura comforts Spock in a turbolift
"If you eliminate the impossible, whatever remains–however improbable–must be the truth."
- - Spock, quoting Sherlock Holmes
"I am as conflicted as I once was as a child."
"You will always be a child of two worlds. I am grateful for this... and for you."
- - Spock and Sarek
- - Spock and Sarek
"I'm coming with you."
"I would cite regulation, but I know you will simply ignore it."
"See? We are getting to know each other."
- (Kirk slaps Spock on the shoulder.)
- - Spock and Captain James Kirk, when Kirk offers to help Spock on an almost suicide mission
"So, her first name is Nyota?"
"I have no comment on the matter."
- - Captain James Kirk and Spock, when Kirk asks if "Nyota" is Uhura's first name
"Captain, what are you doing?"
"You show them compassion, it may be the only way to earn peace with Romulus. It's logic, Spock. I thought you'd like that."
"No, not really. Not this time."
- - Spock and Captain James Kirk, after Kirk offers to help Nero escape certain death
Sean Gerace, a researcher on the film Star Trek who also appears in the movie, turned the producers' attention on to Jacob Kogan. (audio commentary for Star Trek (film), Star Trek (Special Edition/Three disc Blu-ray))
Placing faith in Bad Robot Productions, Zachary Quinto publicly pursued the role, aware that there was a risk he wouldn't be cast in the part. (Star Trek Magazine issue 145, p. 16) "Zach has always known somewhere in his heart that he was going to play this role," remarked casting director April Webster. (Star Trek Magazine issue 144, p. 29) She further said, "This is something that he's always wanted to play. I guess when you have intention that strong, it sort of became inevitable in this case." Even before casting for the film began, rumors were rife that Quinto would be selected to play Spock. (SciFiNow, issue 27, p. 033)
April Webster and fellow casting director Alyssa Weisberg saw a couple of male actors for the part but Zachary Quinto was one of the first who they recorded auditioning. He was auditioned shortly after Webster began working on the film herself, his performances observed by not only her but also by a casting director friend of hers named Mark Scott. (Star Trek Magazine issue 144, p. 29) Quinto's auditions were taped for producer and director J.J. Abrams, with the realization that the actor's schedule on Heroes would have to be worked around. (SciFiNow, issue 27, p. 033) "We didn't put that many [actors] on [tape] because truly, once Zachary Quinto did it, we knew he was Spock," Webster recalled. His physical appearance was a huge part of what made Quinto an appealing option for the casting department, who found him to have a striking resemblance to how original Spock actor Leonard Nimoy looked in his own youth. (Star Trek Magazine issue 144, p. 29)
While J.J. Abrams was considering Zachary Quinto for the role, Leonard Nimoy himself had some limited involvement in the casting. He later explained, "J.J. [...] sent me some footage of Zachary's previous work. I immediately saw the value. He looked to me to be believable, but probably more importantly, he showed great intelligence as an actor, and a great internal life, which I think is terribly important for the Spock character. I called J.J. immediately and said 'I think you've found a wonderful choice.'" (Star Trek Magazine Souvenir Special, pp. 67-68)
Despite his degree of physical similarity to Leonard Nimoy, auditioning Zachary Quinto for the role nevertheless involved multiple iterations of his performance. "We had poor Zach do it 12 different ways – we didn't know what we were looking for, really. We didn't know if they wanted the controlled Spock, or the Spock where we see his human side," stated Webster. "We played with it a million ways and just showed J.J. everything." (Star Trek Magazine issue 144, p. 29) Thus, attempting to adopt the character of Spock at first proved somewhat challenging for Quinto. "That's a very tough part [for] anyone to play," Webster mused. "Even if you look like them, it's a hard part for someone to play. How do you play someone caught between these two personalities? Or caught between these two realities of having been shamed his whole life for being half human, and having that aspect of himself in control all of the time? I think that Zachary really found a fine line there for us. In the end, his casting was a no-brainer." Indeed, Quinto was, according to Webster, cast "almost right away." He subsequently opined that one element which helped him attain the role was that he personally related to the duality inherent in the character. "I think that there are many experiences that I've had," remarked the actor, "that informed this iteration of the character and where he is in this journey." (SciFiNow, issue 27, pp. 032 & 033)
Zachary Quinto signed up to play Spock before having read the script for Star Trek. Once he read the screenplay, he was satisfied that he had made the right choice, later stating, "The complexity of the story, the deeply rooted internal conflict, the vulnerability that Spock comes up against in this film was really compelling to me as an actor [....] One thing really leads to another in a great way for my character." (Star Trek Magazine issue 145, p. 16)
The reserved emotionality of the character continued to be vital to Zachary Quinto, throughout the making of the movie, and was also important to Jacob Kogan. The latter actor mused about the role, "Pretty much, if you're playing a part that is trying to keep their emotions in, then that's the emotion you're trying to convey [.....] I feel like it's not exactly showing your emotions but showing your motives and if Spock's motive is to hide his emotions, then that's what he's showing."  Quinto similarly commented, "For me as the actor playing the character, there was so much that had to be contained throughout Spock's journey." (Star Trek Magazine issue 145, p. 16)
Because Leonard Nimoy has earlobes whereas Zachary Quinto doesn't, lobes were intentionally sculpted into Quinto's prosthetic ears for his appearance as Spock, in order to match Nimoy's ears. (Star Trek Magazine issue 155, p. 56) Quinto's ear prosthetics encompassed most of both his ears. A prototype clay sculpture of Quinto with Vulcan ears, though without hair, was also created by Proteus FX makeup effects supervisor Barney Burman, who was credited with designing and creating the film's aliens. (Cinefex, No. 118, pp. 47 & 52) Quinto's first makeup screen test as Spock was in October 2007 and included his own hair but a pair of prosthetic ears. (Star Trek Special Edition/Three disc Blu-ray documentary featurette "To Boldly Go")
To further enhance Zachary Quinto's appearance as Spock, Makeup Department Head Mindy Hall shaved Quinto's eyebrows and replaced them with hair that she used to create more sharply angled eyebrows, after which Hair Department Head Terrell Baliel added a custom wig. (Cinefex, No. 118, p. 47) Upon preparing for the filming of the untitled Star Trek sequel, Quinto described the requirement of having his eyebrows shaved for the role as "definitely the most tedious part of playing Spock." He went on to say, "The first time, it took three weeks for them to come back in a way that I didn't have to wear my glasses every day to hide them. It was probably two months before they were really thick and bushy again."  On the other hand, Quinto did value the makeup and hair required for the part, generally. "The hair and makeup process is incredibly important for a character like Spock, who is so inextricably identified by his aesthetic," said Quinto. "It informs a tremendous amount of his cultural identity. The process took about two hours, and around halfway through that time I felt a shift within myself – a kind of emergence that would bring the character to life for the remainder of the day." (Star Trek - The Art of the Film, p. 63)
Quinto and Kogan's performances as Spock were not influenced by each other, with neither of them seeing one another's acting until after the film Star Trek was produced.  Quinto instead took inspiration from Leonard Nimoy's past portrayal of the character. They "spent a great deal of time getting to know each other and talking before I started shooting," Quinto explained, "and in all that time, I was also doing my own stuff. Leonard and I watched two Spock-centric episodes together – 'Amok Time' was one of them – and we talked about the character and the experience of shooting them. Most of my work was done on my own – a lot of research and reading – or with Leonard before we started shooting. While we were shooting the movie, I would watch old episodes of the show in my trailer when I was hanging out in there, just to keep me rooted in the specificity and uniqueness of the world [....] When I saw [the film], it made so much sense that my version of Spock would evolve into [Nimoy's]." (Star Trek Magazine issue 145, pp. 18 & 19) Nimoy himself offered, "When Zachary and I met for the first time, he had already done a lot of research on his own. He had a good sense of what it was all about. We did spend quite a bit of time together, but it was more getting to know each other, than any specifics like how to do the Vulcan grip. It was really something terribly important: an understanding of the internal life of this character. What of mine came to the character, and what of his could come to the character." (Star Trek Magazine Souvenir Special, p. 69)
Leonard Nimoy was ultimately very impressed with how Zachary Quinto assumed the role of Spock in the film Star Trek. "I found Zachary Quinto did things with the character that had never occurred to me, which I found quite delicious," Nimoy enthused. "I think he really has found a way to expand the character while at the same time, if you can understand what I'm trying to say, being true to the character. He has found ways to enrich the character. He's wonderful and I'm really proud of what he has done." (Star Trek Magazine Souvenir Special, p. 69) Nimoy also reckoned about Quinto, "I think he could have a great career as Spock: if he wants it, it's there for him." (Star Trek Magazine issue 145, p. 56)
In the novelization of Star Trek, Spock says that he is going to be the first Vulcan in Starfleet. However, this would seem to contradict T'Pol enlisting in Star Trek: Enterprise, although he may be referring to the Federation Starfleet, as opposed to the United Earth Starfleet.
Zachary Quinto and Leonard Nimoy also lent their voices to Star Trek Online, where they play an Emergency Medical Hologram and Spock, respectively; the EMH serves as a guide in the game tutorial while Spock serves as a narrator.