Spock has finally arrived on Star Trek: Discovery, and the eighth episode of season 2, "If Memory Serves," has shed new light on one of the Vulcan's most enjoyable traits: his affinity for bantering with humans. For decades, fans of classic Star Trek have enjoyed Spock's debates with Dr. Leonard "Bones" McCoy, and the CBS All-Access series has revealed that his original human sparring partner was his adopted sister, Michael Burnham.

In "If Memory Serves", Michael and Spock travel to Talos IV - home of the Red Angel. Spock's healing process required the Talosians to delve into his and Michael's family issues, and we learned that when Burnham ran away from home (to spare Sarek's family from being targets of Vulcan logic extremists looking to purge humans from their planet), she cruelly tried to sever Spock's emotional ties to her with insults. Spock was just a little boy and it worked; their relationship was never the same, and the Vulcan never forgave his sister.

Related: Star Trek: Discovery Is Making The Unaired Pilot More Important

While he may be Star Trek's most famous Vulcan, Spock is also half-human, which is one of the reasons why he's such a fascinating character. Spock is perpetually caught between two worlds and two cultures. His outer facade is unflappable Vulcan logic, but, as seen on Star Trek: Discovery, in his earlier years in Starfleet Spock was a bit more emotional and, even as he aged, it was his undeniable human side that regularly manifested when he bantered with Dr. McCoy.

Spock And Dr. McCoy Are Star Trek's Best Frenemies

In Star Trek: The Original Series and in the six feature films starring the classic cast, no one enjoyed getting a rise out of Spock more than Bones, his best frenemy. They were oil and water on the bridge of the Starship Enterprise: Spock was proudly logical while McCoy was the epitome of a "flawed, emotional human". But the doctor also reveled in needling the Vulcan and made it a point to irritate him - and he often succeeded. Bones knew there was a human side to Spock and, though the Science Officer loathed to it it, Spock enjoyed giving as good as he got, firing back wry but scathing jabs at Bones - with an amused but exasperated Captain Kirk usually caught in the middle of his two best friends' bickering.

It was relentlessly entertaining to see Spock irritated by Bones' penchant for "irrelevant" metaphors and mocking his pointy ears and green blood. The classic repartee between Leonard Nimoy and DeForrest Kelley was successfully duplicated in J.J. Abrams' movie reboot; Zachary Quinto's Spock and Karl Urban's McCoy also hilariously traded zingers, to Chris Pine's Kirk's chagrin.

Sadly, as Nimoy's Spock aged into the 24th century, his appearances inJean-Luc Picard didn't provoke the old Spock's keen wit and neither did the younger versions of the crew of the Starship Enterprise in the Kelvin timeline.

Related: Star Trek: Discovery Explains An Emotional Spock TOS Decision

Spock Learned How to Banter With Humans From Michael

"If Memory Serves" boasted many thrilling moments, especially for longtime fans, but one of the most rewarding was seeing Spock restored to his right mind - and he immediately began to banter with Michael. Their verbal dueling flared up right away; Spock smugly asked Michael if she has any questions of value and she fired back with, "Yes, do you think the beard is working for you?" Burnham is the opposite side of Spock's coin - a human trained in Vulcan logic - but more importantly, she's Spock's sister. They were once close as children but they're now estranged, but being family means they also instinctively know how to irritate each other, which is great fun to watch and is poised to continue as they work together to find the Red Angel.

With Star Trek: Discovery providing new context, it's fascinating to learn that his relationship with Michael, an intelligent human who was also a worthy rival, trained Spock to both seek out and enjoy having a verbal sparring partner in Dr. McCoy.

Next: Discovery Broke Star Trek Tradition For Its Best TOS Reference Yet

Star Trek: Discovery streams Thursdays @ 8:30pm on CBS All-Access and internationally the next day on Netflix.