Doublethink is just a method of continually deceiving oneself into believing that the contradictory thoughts one holds are true. And this is basically accomplished through tactics of willful ignorance and deception. I'm really failing to see how this type of thinking is anything short of delusional. If anything, it's a tendency for sloppy and solipsistic thinking that must be actively avoided.
Doublethink:The faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest arguments if they are inimical to Ingsoc, and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. In short....protective stupidity.
But stupidity is not enough. On the contrary, orthodoxy in the full sense demands a control over one's own mental processes as complete as that of a contortionist over his body. Oceanic society rests ultimately on the belief that Big Brother is omnipotent and that the Party is infallible. But since in reality Big Brother is not omnipotent and the party is not infallible, there is need for an unwearying, moment-to-moment flexibility in the treatment of facts. The keyword here is blackwhite. Like so many Newspeak words, this word has two mutually contradictory meanings. Applied to an opponent, it means the habit of impudently claiming that black is white, in contradiction of the plain facts. Applied to a Party member, it means a loyal willingness to say that black is white when Party discipline demands this. But it means also the ability to believe that black is white, and more, to know that black is white, and to forget that one has ever believed the contrary. This demands a continuous alteration of the past, made possible by the system of thought which really embraces all the rest, and which is known in Newspeak as doublethink.