Originally Posted by Zissou'sMom
Ah, but cats who are never taught to be outdoor cats usually have no desire to go outside, whereas a cat who is a stray will often adjust quite well to indoor-only. IMO, the only cats who should be outside unsupervised are those like Hissy's ferals whose options are often very sadly being outside or being put down by the shelter. My guess is that you don't have to force your cats to come inside except occasionally, while the OP is talking about trying to convince his cat to go outside. You're comparing apples to oranges.
The common argument for letting cats outside unsupervised is often "cats want to go outside" and really there is no other argument for the proven detriments to their health and well-being. But that argument is void here, because this cat does not want to go out and therefore there is absolutely no argument for encouraging it. So, since there are always numerous good reasons for keeping a cat in, and in this case not a single reason for him to be outside, the obvious answer becomes, let the cat stay inside!