"I'm a Time Lord... you don't understand the implications. I'm not a human being; I walk in eternity." The Doctor Never did we feel like the Doctor was an alien, more than when he was Tom Baker. The otherworldly presence of the Fourth Doctor is felt constantly through the seventies, but this quote is one that must have influenced Russell T Davies's decision to give him a godlike aura. For a race of people to have "implications" suggests great power, as if the title "Time Lord" wasn't itself a lofty ascension to the universe's top table. The phrase, "I walk in eternity" though is a beautiful one; it's indicative of the Doctor's travels through history and far into the future, but it's also suggests an agelessness. It's a phrase that evokes the fact that the Doctor will outlive all of his companions. When Tom Baker delivered the line, it felt like a burden; the curse of the Time Lords, the Doctor believes, is that they live too long. This is a quotation that sums that up so brilliantly in so few words.