Anthony Collins, Freethinker

Anthony Collins' classic work published in 1713,  A Discourse of Free-Thinking, is downloadable from Google books or archive.org.

For a detailed outline of Collins' life and work, see:

Anthony Collins (Stanford Encyclopedia of Philosophy)

Collins was also a pioneer viz. the notion of emergent properties!

Of course, don't forget the Wikipedia article on Anthony Collins.

You can check for other books by Collins, but I found this one I don't recall seeing featured in brief bios:

A Discourse Concerning Ridicule and Irony in Writing (1729).