Lillelara

As long as the innocence of Dickie Greenleaf was debatable in the opinion of the police, it was suicidal to think of leaving the country as Dickie, because if he had to switch suddenly to Tom Ripley, Ripley´s passport would not show that he had left Italy. If he wanted to leave Italy - to take Dickie Greenleaf entirely away from the police - he would have to leave as Tom Ripley, an re-enter later as Tom Ripley and become Dickie again once the police investigation were over. That was a possibility.

I´m confused, but still, this has a weird kind of logic to it. 

He definitely wanted to see Greece. He wanted to see Greece as Dickie Greenleaf with Dickie´s money, Dickie´s clothes, Dickie´s way of behaving with strangers. But would it happen that he couldn´t see Greece as Dickie Greenleaf? Would one thing after another come up to thwart him - murder, suspicion, people? He hadn´t wanted to murder, it had been a necessity. The idea of going to Greece, trudging over the Acropolis as Tom Ripley, American tourist, held no charm for him at all. He would as soon not go

Ripley constantly makes up his own reality, telling himself that Dickie´s murder hasn´t been premeditated. 

"Where were you this Winter?"

"Well, not with Tom, I mean, not with Dickie," he said laughing, flustered at the slip of the tongue.