Chapter 14 is called the 'Final Argument'. Which argument is it referring to? What was the result of that argument?

In Chapter Fourteen, Axel’s nerves are stretched. He has nightmares and feels that he can no longer stand his apprehension. He goes to his uncle and tells him his worries about the journey.... the source of conflict between the two. His uncle, however, says that Axel has only been thinking about the dangers of the journey, particularly the possibility of an eruption of Snaefells. His questioning of the villagers and his research have led him to conclude that there will not be one. Axel realizes he has been defeated by scientific arguments and returns to bed.