I don't think Lady R insists on rigid conforming to the norms --on the contrary, one of the points Lady R regarded in Mr Elliot's favour as quoted in Robbin's post above was that Lady believed that Mr E "judged for himself in every thing essential, without defying public opinion in any point of worldly decorum." (Chap 16). To "judge for himself in everything essential", one would have to dare to think for oneself. But "without defying public opinion in any point of worldly decorum" -- I think Lady R means that while it is creditable to think and judge for oneself, it is also polite and proper not to be indecorous or too enthusiastic in expressing one's own opinions, especially if others do not quite agree.