He is mainly remembered for the bitter hatred he inspired in Jonathan Swift, who among many other insults called him a "vile and profligate villain", and compared him to William Scroggs, the Lord Chief Justice of England in the 1670s, who was notorious for corruption.

His grandfather, Mark Quin, had committed suicide in 1674 by cutting his throat with a razor in Christ Church Cathedral, Dublin, apparently because he believed that his wife was unfaithful to him, a fact which Swift and other enemies of Whitshed later seized on to humiliate him.

He did not have any great reputation as a lawyer or as a politician and his rapid rise to power caused some surprise;[6] in particular, his elevation to the office of Lord Chief Justice when he was little more than 35 years old was most unusual, if not unprecedented.

Ball attributes his success to his family's wealth and political connections, and the friendship of William King, Archbishop of Dublin, who had considerable though not unlimited influence over judicial appointments.

[8] This time the result was a complete failure: although Whitshed spared no efforts, interviewing the jurors individually, they refused to give a guilty verdict against Harding.

Swift's friends joined the battle, and even painful personal details like the suicide of Whitshed's grandfather, and his grandmother's supposed adultery, were dragged up: "In church, your grandsire cut his throat... [your] grandame had gallants by the twenties, and bore your mother to a prentice".

The following year it was decided to make him Chief Justice of the Irish Common Pleas, but he died suddenly, aged only 48, shortly afterwards.