 = Katherine Pulaski = 
 
 Commander Katherine Pulaski is a fictional medical doctor in the American science fiction television series Star Trek : The Next Generation . She is the chief medical officer aboard the Federation starship USS Enterprise @-@ D. Her medical skills saved the lives of Captain Jean @-@ Luc Picard and Commander William Riker , and she helped inspire Lt. Commander Data to create a hologram of Professor Moriarty that became self @-@ aware . Pulaski preferred to avoid the transporter , but was forced to rely on it to save her own life from an alien infection . Before arriving on the Enterprise @-@ D , she previously served on the USS Repulse . For a time , she was romantically involved with Kyle Riker , but they continued to remain friends . 
 Portrayed by American actress Diana Muldaur , Pulaski replaced the character of Commander Beverly Crusher for the second season after Gates McFadden 's contract was not renewed . Pulaski first appeared in the second season opener " The Child " , and made her final appearance in " Shades of Gray " . Before playing the role of Pulaski on The Next Generation , Muldaur appeared in Star Trek : The Original Series , playing different characters in the episodes " Return to Tomorrow " and " Is There in Truth No Beauty ? " She later worked with series creator Gene Roddenberry on a pilot for the series Planet Earth . McFadden returned to replace Muldaur in the third season , reprising her role as Dr. Crusher for the remainder of the series . 
 Reviewers criticized Pulaski 's approach , as well as her inability to fit in with the crew . Critics noted that her transporter phobia was reminiscent of Dr. Leonard McCoy from The Original Series , as was her relationship with Data ; Pulaski 's interaction with Data raised comparisons to that of McCoy and Spock from The Original Series . Episodes featuring Pulaski in a leading role , such as " Unnatural Selection " , produced divided opinions among critics , with some describing it as a key episode while others argued that it showed only the negative side of her role . 
 
 = = Concept and development = = 
 
 Towards the end of the first season of Star Trek : The Next Generation , staff members convinced Gene Roddenberry to drop Gates McFadden as Dr. Beverly Crusher from the show . Executive producer Rick Berman opposed this decision . To allow for McFadden 's return in the future , Roddenberry wrote Crusher 's character out rather than killing her . McFadden 's departure led to an opening for a new cast member . The producers contacted American actress Diana Muldaur , unaware of her past involvement with Roddenberry 's Star Trek and Planet Earth pilot . In The Original Series , Muldaur played the role of a doctor in two episodes : as Dr. Ann Mulhall in " Return to Tomorrow " , and as Dr. Miranda Jones in " Is There in Truth No Beauty ? " Muldaur also worked on the pilot for Planet Earth after getting to know Roddenberry and his wife , Majel Barrett , through their annual Star Trek Christmas parties . 
 Muldaur was not required to audition for the role of Pulaski . Instead , she was given 15 VHS cassettes of the first season . She found it " very exciting " , noting it " got better and better and better " as she watched it . Christina Pickles was also considered for the part of Pulaski , a decision Berman described as " very tough " . Muldaur finally agreed to play the role , but asked Roddenberry to change the name of the character to Kate , which became Katherine . The character of Katherine Pulaski was modeled on Doctor Leonard McCoy from The Original Series . Like McCoy , Pulaski feared transporters and disliked unemotional colleagues . The dynamic between McCoy and Spock was revisited with the relationship between Pulaski and Lieutenant Commander Data . Muldaur believed that Roddenberry deliberately created the parallel between the two characters on the two shows . 
 Katherine Pulaski debuted in the second season episode " The Child " , with Whoopi Goldberg making her first appearance of the series as Guinan in the same episode . Even though Muldaur was a regular character on The Next Generation , she was only listed in the opening credits as a " Special Guest Star " . Overall , Muldaur described her experience portraying Pulaski as " hard work " . She expected to be cast for just one season , but was unaware of who would succeed her after she left . Following production of the second season , Muldaur left the series and joined the cast of L.A. Law . She used footage of the episode " Unnatural Selection " to gain the part . Gates McFadden returned to continue her role as Dr. Crusher on The Next Generation for the remainder of the series . 
 
 = = Appearances = = 
 
 Pulaski 's background is touched upon in the episode " The Icarus Factor " . She was previously romantically involved with Commander William Riker 's father Kyle Riker ( Mitchell Ryan ) , after she was part of a rescue team responding to a Tholian attack on a Federation Starbase . She realised that a romantic relationship with Riker would not work , but they remained friends . Directly prior to serving on the Enterprise @-@ D , she served on the USS Repulse under Captain Taggart , who was sorry to lose her . 
 In , " Elementary , Dear Data " she challenges Lt. Cmdr Data to solve an original Sherlock Holmes mystery on the holodeck . He accepts her challenge , which results in the creation of a self @-@ aware hologram of Professor Moriarty ( Daniel Davis ) . Pulaski joins Data and Lieutenant Geordi La Forge ( LeVar Burton ) , but is captured by Moriarty who also takes over manual control of the Enterprise . Moriarty demands that they find a way to enable him to leave the holodeck , but is persuaded by Captain Jean @-@ Luc Picard ( Patrick Stewart ) to release control and be stored within the ship 's computer memory until a means can be found to grant his wish . ( Years later , Moriarty is released from the computer and takes control of the ship 's computer , again demanding his freedom . He is finally tricked into thinking that his wish was granted , but remains trapped inside a computer simulation ( " Ship in a Bottle " ) . ) 
 Pulaski 's apprehension at using the transporter was evident in " The Schizoid Man " , where Dr. Selar ( Suzie Plakson ) went with the away team instead of Pulaski , as it required her to beam over to a transport vessel . However , the transporter would later save Pulaski 's life in " Unnatural Selection " , after she was infected with a disease from the planet Gagarin IV that accelerated her aging process . She uses the transporters to remove the infection and is returned to health . 
 She demonstrates her medical expertise on several occasions . In " Time Squared " , Pulaski discovers that the duplicate Captain Picard is out of sync in time and will slowly improve until he returns to the point at which he left . In the episode " Pen Pals " , Picard orders Pulaski to wipe the memories of a young girl called Sarjenka , whom Data had been corresponding with and helping in violation of the Prime Directive . Whilst in " Samaritan Snare " , she is summoned to Starbase 515 to perform heart surgery on Captain Picard as she is the most experienced surgeon nearby . This is despite Picard 's wish for her not to perform the surgery , due to his concern with the image it might give to the crew . 
 When the Enterprise arrives at the lost colony of Mariposa in " Up the Long Ladder " , the Mariposans kidnap Pulaski and Commander William Riker ( Jonathan Frakes ) and steal their DNA to clone new members of their colony . Although technologically advanced , the Mariposans lack genetic diversity . When Pulaski and Riker discover the clones , they destroy them . Picard helps resolve the dispute by suggesting the Mariposans allow the Bringloidi , a preindustrial , rural people whose colony was destroyed , to migrate to their world . The Mariposans , however , have relied on cloning for 300 years , and no longer sexually reproduce . Pulaski notes that with time , they will become familiar with the practice once again , and recommends that the Mariposans form large , group marriages with the Bringloidi to create a healthy population . 
 Following Data 's defeat at a game of Strategema in " Peak Performance " , Pulaski and Councillor Deanna Troi ( Marina Sirtis ) attempt to console him , but it is left to Captain Picard to convince Data that he is not malfunctioning . Pulaski 's final appearance on The Next Generation was in the episode " Shades of Gray " . When Commander Riker falls ill to a dangerous virus during an away team mission , Pulaski drives out the virus with a device that stimulates his memory centre . After she discovers that negative memories are more effective in removing the virus , she uses memories of fear and survival to save Riker 's life . 
 In the alternative future timeline portrayed in " Endgame " , the Star Trek : Voyager finale , Pulaski is said to have worked at the Starfleet Medical facility in San Francisco . 
 
 = = = Novels = = = 
 
 Pulaski appears in several books of the non @-@ canon novel series based on the adventures of the crew in The Next Generation and elsewhere in the same time period . In Peter David 's novel Vendetta ( 1991 ) , Pulaski is reassigned to the Repulse under Captain Taggart following her departure from the Enterprise . In Star Trek : Progress ( 2006 ) , a Starfleet Corps of Engineers book by Terri Osborne , Pulaski is on board the USS Progress when it visits Drema IV , as she wants to check up on the progress of Sarjenka , a young girl from The Next Generation episode " Pen Pals " . Pulaski also appeared alongside Wesley Crusher and Guinan in Michael Jan Friedman 's " All Good Things ... " ( 1994 ) , a novelisation of the The Next Generation series finale . 
 
 = = Reception and commentary = = 
 
 In their 1998 book , Star Trek 101 , Terry J. Erdmann and Paula M. Block called " Unnatural Selection " the key Pulaski episode . Science fiction writer Keith DeCandido felt that she displays all of her worst traits in this episode , including " her stubbornness , her intensity , her constant interrupting of people , her bitching out Data ( though at least this time she apologizes to him when he expresses concern over her health ) , and ... transporter @-@ phobia , because apparently she wasn 't enough like Dr. McCoy yet . " DeCandido described Pulaski as " annoying " and noted that this feeling was mirrored on screen by Captain Picard . In Science Fiction Television : A History , author M. Keith Booker observed that " Pulaski never quite meshed with the rest of the crew " . 
 The events of " Elementary Dear Data " led film professor Zoran Samardžija to suggest that Pulaski may have been inspired by the works of Friedrich Nietzsche . In Sherlock Holmes and Philosophy : The Footprints of a Gigantic Mind ( 2011 ) , Samardžija notes that Pulaski 's argument that Data lacks intuition is reminiscent of parts of Nietzsche 's 1878 work Human , All Too Human . The relationship between Pulaski and Data was further considered by Rhonda V. Wilcox in her article " Dating Data : Miscegenation in Star Trek : The Next Generation " ( 1993 ) . Wilcox notes that Pulaski " frequently challenges Data in terms of his machine nature , expressing scorn for his supposed insensitivity . " She compares Data 's emotionless state to slavery due to the reference in " The Child " to Maya Angelou 's 1969 work I Know Why the Caged Bird Sings . 
 
 