I agree with Line and Tom P2 on the lecturing quality of the “nut” speech. Frederick has been preaching, dangerously I think, the cult of “Let those who would be happy be firm” to an adoring and impressionable young woman when he is really not thinking much of her at all. IMO he does not realize how Louisa will perceive what he says because Henrietta’s indecision and Mary’s interference has refocused his attention on Anne’s (in his eyes) ultimate failure of character. He misses that Louisa’s main purpose in persuading her sister to visit their cousins was to remove competition for his attention. I think although it is said in the third person his comment, “If Louisa Musgrove would be beautiful and happy in her November of life, she will cherish all her present powers of mind.” is taken in a more intimate way than he intended. It is telling Louisa firmness of mind is important to him and he links that to her future happiness. It is almost saying if you are of firm mind you are the girl for me—it is no wonder Louisa does not know what to say in response. She does however know what to do in response and exhibiting her firmness of mind is what leads to her fall at the Cobb. (;D)