The third Doctor had no sooner been exiled to Earth when he began working alongside the military organisation, UNIT. Robbed of the use of the TARDIS this Doctor was no longer able to explore. Instead he effectively had a job.
As scientific consultant it was his job to wait for the call to arms, defending the Earth from invasion and investigating anything the government wanted looked into. The Doctor always looked for a peaceful resolution where possible but he couldn’t have helped but see how effective the soldiers were at their job. Some of them were even becoming his friends.
Here were allies who could be given objectives and had the skills and training to execute the Doctor’s plans. Liz Shaw was almost an equal, helping the Doctor solve problems much more quickly than if he had been alone. Although less disciplined Jo Grant had the same military focus and determination.
This was a far cry from such teenaged companions as Ben & Polly, Vicki or Dodo. Davros would later accuse the Doctor of turning his companions into weapons. Is it this period where the Doctor picked up this trait?
Confronted with strong willed superiors the Doctor had to cultivate his own sense of authority, using his status as the smartest man in the room to demand attention. It didn’t always work but it was often enough to ensure his plans succeeded.
He even gained his own nemesis, in the form of the Master. The Doctor seemed to enjoy matching wits with the Master. Was it just the challenge it presented him or did his ego appreciate someone being so fixated on him. Did he think this made him special.
It was also during the Third Doctor’s tenure that the Sonic Screwdriver was introduced. It appeared that his attitude to introducing advanced technology into a time period had altered.
Indeed, there are several instances where the Doctor’s actions would have drastically altered the time line. The greatest example of this is his attempt to convince the humans to live alongside the newly discovered reptile race in ‘The Silurians’.
Things would have undoubtedly been improved had both species listened to him but the Doctor had to have known from his previous trips to Earth’s future that this didn’t happen. Either he had decided that being stranded in one time period meant the normal rules didn’t apply or he’d come to believe that the web of time was worth sacrificing for the greater good.
Certainly he could not ignore the fact that the Time Lords had deliberately chosen this section of time to place him. It would have become obvious very quickly that had he not been there Earth’s history would have been changed by the successful alien invasions. In exiling him to Earth the Time Lords had given him their unspoken consent to change things.
Towards the end of his exile the Doctor was sent on several missions by the Time Lords. This could have only reinforced his self image as an agent of good. His trips through time now had a real purpose, with a goal in place even before he stepped out of the TARDIS.
The first time the Doctor died it was due to old age, the second time it was forced upon him as punishment. This time the Doctor sacrificed himself to save the universe from giant spiders. It is this act that cemented that he was a hero, willing to die for others.
Although quickly leaving the company of UNIT the fourth Doctor found himself being charged with several missions over the course of his life. One of his earliest quests was a mission for the Time Lords to wipe the Daleks from history.
It is during ‘Genesis of the Daleks’ that he is faced with the morale dilemma of if he has the right to destroy them. They are unquestionably evil but the real issue is does he have right to change history.
In the short term the Daleks would be prevented from bringing death across the universe but the Doctor has to weigh that against all the positive events that would come about as a result, that would also be lost.
Ultimately the Doctor decides that he does have the right, although he doesn’t complete his mission. This doesn’t change the fact that at this point in his life the Doctor is unsure that he should make big changes to time, even if evil will be vanquished as a result.
Earlier the Doctor had presented Davros with his own ethical dilemma. Would Davros release a deadly virus that could wipe out all life. Davros decides that he would because the power to make that choice would make him a god.
The question must be asked then, do the later incarnations of the Doctor make such a huge impact because he believes it is the right thing to do or because he enjoys the god-like status it gives him?
Later the Doctor is charged by the White Guardian to recover the Key to Time. Of all the people this cosmic entity could have chosen it picked the Doctor. Did the responsibility give the Doctor a sense of pride?
With the Key of Time assembled the Doctor considers the ramifications of anyone controlling such a powerful artefact. Even if a person has benign intentions should they be given access to such a resource?
The Doctor decides that no one should have the Key to Time. This suggests that at this point he believes that a struggle should exist between good and evil, with neither side being able to overpower the other.
It is also worth noting that the 4th Doctor briefly becomes President of Gallifrey. It is a ruse but the fact remains that his plan relies on having power. In certain situations having such a lofty status benefited him.
Still the Doctor was presented as being far less than perfect. Romana would tease the Doctor at his low scores at the Academy, something that the Doctor doesn’t refute. Upon returning to Gallifrey in ‘The Deadly Assassin’ his fellow Time Lords do not view him as someone of an special note.
There were still indications that the Doctor had some interest in using the TARDIS for the purposes of exploration. His trip to Victorian London with Leela in ‘The Talons of Weng-Chiang’ and to Paris with Romana in ‘The City of Death’ show that he could still get some pleasure from time travel.
Again the fourth Doctor died saving the universe. How many times can man die for something before he starts feeling that he is owed something in return?