Answer: No. But, he was the first in the colonies to write about the subject quite extensively.

In the year 1644, Roger Williams published his "Bloody" book. Many historians consider The Bloudy Tenent of Persecution his most famous work. He wrote Bloody after traveling from New England to London and arriving in midsummer 1643. His book was on sale by July 15, 1644.

It is a fierce attack on religious and political intolerance in both Old England and New. He advocated for free thought and belief because he felt that punishing those that did not believe was not part of his faith and government must be separate from religion.

Roger Williams advocated for and wrote extensively about...

...a hedge or wall of separation between the Garden of the Church and the Wilderness of the world.

His ideas raised questions and challenges but his ideas endured over time.

Roger Williams promoted the concept of liberty of conscience; of freedom of and from religion.

A good example of how Roger's concerns differed from aristocratic traditions of the time is demonstrated in the preface of his "Bloody" book.

“Two mountains of crying guilt lie heavy upon the backs of all men that name the name of Christ, in the eyes of Jews, Turks, and pagans.
First, the blasphemies of their idolatrous inventions, superstitions, and most unchristian conversations.
Secondly, the bloody, irreligious and inhuman oppressions and destructions under the mask or veil of the name of Christ, etc.” --R.W., preface to Bloudy.

In the above passages, Roger Williams was concerned with how Christians were being perceived by “others”, and how Christians were using their religion to justify various punishments on those that did not believe.

The seeds of freedom and liberty he sowed, lasted. For example, in 1802 Thomas Jefferson authored a letter with the following passage:

"Believing with you that religion is a matter which lies solely between Man & his God, ...the legitimate powers of government reach actions only, & not opinions, ...the whole American people which declared that their legislature should make no law respecting an establishment of religion, or prohibiting the free exercise thereof, thus building a wall of separation between Church & State." --Thomas Jefferson, January 1, 1802

Unverified, but most genealogists use 1676. If so, Mary reached 66 years of age and died in Providence in 1676 about a year into the King Philips War. I have yet to find a record of how she died. I'm still researching.

Answer: I don't know. He wrote about freedom of conscience, and that government did not rule over your soul, but I have yet to find the phrase "soul freedom" in his writings. I'm sure it's there, but it's definitely not common despite the fact that many attribute the phrase "soul freedom" so willingly to him.

The closest I've found so far is in a letter to John Winthrop dated July 31, 1637.

"...how could he unles he might enioy the freedome of his Soule and Conscience."