Annus Mirabilis - John Dryden
Second Treatise on Government - John Locke
Leviathan - Thomas Hobbes
A Dictionary of the English Language - Samuel Johnson
Answer:
They cannot be easily forged or manipulated
Contrasts the good and bad herbs, explains to audience his use of herbs, describes his role as friar, and (this one I'm not fully sure about as it has been a while since I last read this play) warns Romeo about eating certain herbs.