Arthur Dent is a paradoxical character with strangely contradictory traits. Nonetheless, he has one consistent characteristic displayed throughout. He is full of determination and insistence on his way of life. This is evident when he goes out after having his morning routine interrupted and fights with the people trying to bulldoze his house down. It is this trait that keeps him going through all the strange and bizarre events in the story.
On the other hand, his gullible, credulous, naivete whereby he accepts what Ford Prefect tells him to do with relative ease is a contrast to his stubborn resistance against the bulldozers. His gullibility and naivete are also contradicted by his questioning nature. All through the story, Arthur Dent asks question after question in absurd situation after absurd situation.
Which leads to mention of his absurd trust. He goes where ever any strange person says to go, but a contradictory quality to his absurd trust is his courage. Usually absurdly trusting people don't need to be courageous because they never perceive danger, and usually courageous people are not absurdly trusting because they know danger when they fall into it.