All we then want is to proclaim a truce with reason, and to be pleased with as little expense of thought or pretension to wisdom as possible. This licensed fooling is carried to its very utmost length in Shakespeare, and in some other of our elder dramatists, without perhaps sufficient warrant or the same excuse. Nothing can justify this extreme relaxation but extreme tension. Shakespeare’s trifling does indeed tread upon the very borders of vacancy; his meaning often hangs by the very slenderest threads. For this he might be blamed if it did not take away our breath to follow his eagle flights, or if he did not at other times make the cordage of our hearts crack.
By William Hazlitt (1778–1830) via bartleby.com
Above sentences are extracted from William Hazlitt's prose. You can click the link above to read the whole passage.
I have no idea when reading the phrase of "Shakespeare’s trifling does indeed tread upon the very borders of vacancy";
I try to understand it as: when Shakespeare talked (or wrote) in a jesting, he did all his best, and used all his energy to make it more funny.
Is my understanding correct? Anyone has different opinions?