Sensibility

It took me a while to get this out because I don't have a whole lot that is new to say on the subject. A good modern word for sensibility might be "responsive".

And while sensibility is not a purely erotic phenomenon, a good way to get a handle on sensibility is to think of it as analogous to sexual responsiveness. You might say that a person incapable of sensibility has the same disadvantages in relating to the world as a person who is incapable of responding sexually has in relating to their spouse. Which is to say, it can be done and is done but not nearly as well as people who do have the ability to respond can do.

This analogy works because sexual responsiveness is part of sensibility and anyone who is paying attention to what goes on in Austen will see that this erotic responsiveness is a key part of the characters of Catherine Morland, Elinor and Mariann Dashwood and Elizabeth Bennett.

Sensibility is a virtue but it needs other virtues to balance it.

Although it is a virtue it can easily be characterized so that it looks like narcissism. For related reasons, what is only narcissism and nothing more (see Isabella Thorpe and Lydia Bennett) can be disguised so as to look like sensibility.