Sarah Caudwell said this quote

I should explain — in view of my last letter, you may find it slightly surprising — that Daphne and I are now bosom friends. That is to say, she seems to think we are; and I do not feel that I know her well enough to dispute it.

~ Sarah Caudwell

Julia's unhappy relationship with the Inland Revenue was due to her omission, during four years of modestly successful practice at the Bar, to pay any income tax. The truth is, I think, that she did not, in her heart of hearts, really believe in income tax. It was a subject which she had studied for examinations and on which she had thereafter advised a number of clients: she naturally did not suppose, in these circumstances, that it had anything to do with real life.

~ Sarah Caudwell

On my first day in London I made an early start. Reaching the Public Record Office not much after ten, I soon secured the papers I needed for my research and settled in my place. I became, as is the way of the scholar, so deeply absorbed as to lose all consciousness of my surroundings or of the passage of time. When at last I came to myself, it was almost eleven and I was quite exhausted: I knew I could not prudently continue without refreshment.

~ Sarah Caudwell

In order to deceive others, it is necessary also to deceive oneself. The actor playing Hamlet must indeed believe that he is the Prince of Denmark, though when he leaves the stage he will usually remember who he really is. On the other hand, when someone's entire life is based on pretense, they will seldom if ever return to reality. That is the secret of successful politicians, evangelists and confidence tricksters—they believe that they are telling the truth, even when they know that they have faked the evidence. Sincerity, my dear Julia, is a quality not to be trusted.

~ Sarah Caudwell