Jacques wants to become better acquainted with Rosalind (as before in her disguise as Ganymede), but she is reluctant because he is so melancholy. Jacques openly admits his moody condition, and he asserts that his excessive melancholy makes him more comfortable than being excessively happy.
Rosalind criticizes him and comments that both those who are excessively morose or gloomy and those who are excessively merry or happy “are abominable” to others (line 5). Such people, she tells Jacques, are worse than drunkards because drunkards eventually become sober; but the excessively moody or emotional never improve. She is suggesting that he should find balance, that he should control his emotions. Once again, Shakespeare is inserting a comment upon the Reason vs. Emotion conflict. Rosalind is instructing Jacques to be reasonable, but his emotions are too strong for him to do so.
Jacques argues that being sad (meaning both melancholy and serious) and saying nothing is an admirable quality, but Rosalind disagrees and suggests that a person who is sad and quiet is no better than a post.
So, Jacques then launches into a defense of his melancholy and declares that his condition is