The 3 books contain essential Shakespearean "dialectical" principles of human(1), social(2), and political(3) moral behaviour (‘If any man delight to haue himselfe shine with a glorious shewe of virtue, I haue giuen him the toppes of moral behauior;)
Chapter 42 in Book-3 ("Of Poetrie") strongly reminds to Marlowe's basic "dialectic complementarities" and his "life motto" "Quod me alit me destruit" :
Excerpt: The fault is not in the Art of Poetrie, but rather in the men that abuse it.-Poets themselves may bee traitours and felons, and yet Poetrie honest and unattainted. Take away the abuse, which is meerely accidental. and let the substance of Poetrie stand still. Every thing that bringeth pleasure, may bring displeasure.- Nothing yeeldes profit, but the same may yeeld disprofit. What is more profitable then fire? Yet notwithstanding we may abuse fire, and burne houses, and men in their beds. Physicke is most commodious for mankind, yet we abuse it, by administring of poisened potions...
The contextual connections between thoughts and knowledge of Shakespeare on the one side and Vaughan on the other never seem to have been investigated in detail.