Signor Pietro Baglioni, Professor of Medicine in the University, a physician of eminent repute,....
Professor Baglioni is a doctor of great fame and prestige (i.e, "eminent repute") in Padua. He is an elderly man who is friendly and pleasant and who enjoys a good feast with good wine (i.e., "genial nature" "jovial"). He generously has guests, like the student Giovanni, to the entertainment of dinner. He readily enters into enthusiastic and unrestrained conversation without any reserve or pomposity of bearing (i.e., "freedom and liveliness of his conversation").
With all this friendliness, openness, joyful pleasantness and conversability, Giovanni is surprised when Baglioni replies in an intent negative attitude to his query about Rappaccini:
[Rappaccini] cares infinitely more for science than for mankind.
Nonetheless, Giovanni recognizes the truth Baglioni speaks since he too has his own doubts about Rappaccini. Thus Hawthorne represents Baglioni as a man of great openness of heart yet one who can recognize and disapprove of unscrupulousness in his colleagues. In other words, Baglioni is a complex character with an involved nature who knows more than perhaps he is willing to reveal and who is capable of deep emotion and commitment, which is important for his role in the surprise, and somewhat anticlimactic, ending of the story.
“[Rappaccini] has seen you! — he must have seen you!” said Baglioni, hastily. “For some purpose or other, this man of science is making a study of you. I know that look of his! It is the same that coldly illuminates his face, as he bends over a bird, a mouse, or a butterfly, ... Rappaccini! Rappaccini! And is this the upshot of your experiment?"