What fact does Winston believe saves his humanity in 1984?This question is on chapter three of book three. I have had a couple very vague ideas but...

He has some dreams that through his diary he can create a
reality that will trump the one he lives in.  He never states that he's writing it for
that reason, but why else would he go through all the trouble and risk?  He believes
that there exists a thing that we might call "the human spirit" and that that spirit is
indominable and will ultimately triumph.  This is, of course, total nonsense.  Winston
believes that through the power of will he can (and always will) believe that 2 + 2 = 4.
 What he learns is that it's totally relative, that he can be made not only to say that
2 + 2 = 5 but to believe it.  He totally misunderstands the role of power, power that is
executed not "for the good of humanity," but for it's own sake, power exercised without
excuse, power that only exists to procreate itself.  Next to that, his belief in "the
human spirit" pales.

As a generally liberal society, we
tend to take Winston's position, that there is an essential humanity that will always be
around, that good will prevail over evil (why do we believe this?), essentially that
goodness with trump power.   I suspect that Orwell is warning us that if we are not
vigilant, power will win; this echoes Jefferson's warning about the price of freedom
being eternal vigilance.

Great
book!