As expected of the language of Shakespeare, insults are rampant even in this short passage. There is an exchange of name-calling between the two suitors. Lucentio calls Hortensio "too forward" (presumptuous) and "preposterous ass," while the latter calls him "wrangling pedant" (bickering scholar) and "base knave" (a tricky deceitful fellow of low status) (http://www.m-w.com/cgi-bin/dictionarybook=Dictionary&va=knave).
The younger suitor is more blatant in his insults, "Spit in the hole, man, and tune again," while the older one makes his second criticism out of his hearing: "[Aside] How fiery and forward our pedant is!/ Now, for my life, the knave doth court my love:/ Pedascule, I'll watch you better yet." Pedascule is used as a "scoffing repetition of "pedant," implying (in Latinised form) that he mentally foots or kicks him with utmost ignominy" (http://www.theatrehistory.com/british/shakespeare031d.html).
Moreover, there is a comparison between philosophy and harmony. ...