] I tend to believe that it's the drive and, more importantly to Isabella, James and possibly Thorpe, the chance to converse alone with an attractive member of the opposite sex. The fact that John refuses to take one of his own sisters in Catherine's stead seems to support this. If this is so, then it's even more selfish, to my mind, for them to pressure her into joining them in this way. For Isabella and James, it isn't her company that they seek, but her presence to make their own meeting appear less improper. For Thorpe, even if he seeks her company because he fancies her, lying to get her into his carriage and forcefully keeping there is hardly a gentlemanly manner of wooing.

I think that this might be a very important aspect and motivator for these outings, especially on the part of Isabella (and James). I don't trust John, however. He certainly isn't behaving like a gentleman. And maybe he does have some interest in conversing alone with a member of the opposite sex, but I'm not really convinced it is entirely out of any real attraction for Catherine. Sometimes it seems that he has decided for himself that Catherine is for him, and so proceeds as if it is a fait accompli, that by essentially forcing her to spend time with him and bragging to make himself look good the decision will inevitably become a reality. Other times, however, it seems that Thorpe is interested in the idea of going driving with a young woman, and Catherine is the convenient choice. The acquaintance of Catherine and Isabella make it convenient. The relationship between Isabella and James, likewise. And certainly Isabella as reason to bring Catherine along for reasons you mentioned above. The refusal on Thorpes part to drive out with one of his sisters so as not to look the fool, makes me think that he is more interested in the idea of these drives then he is in driving with Catherine specifically. It seems that he is more interested in how he looks than in who he is with. Could he be wanting to make himself look desirable, in inaccessible, to others, especially young ladies?