Winston writes about freedom and two plus two

Reflecting on O'Brien's face and his belief that O'Brien is on his side, Winston writes in his diary: 'Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.' He feels that the solid world exists, that stones are hard and water is wet, and that the Party's denial of objective reality is the ultimate heresy. The thought of O'Brien gives him courage to write this, though he knows the enormous power arrayed against him. Truisms are true, and he must hold on to that.