It is not strange that men of note and learning, attracted by the wealth of symbolism on Masonry, as well as by its spirit of fraternity perhaps, also by its secrecy began at an early date to ask to be accepted as members of the order; hence Accepted Masons. How far back the custom of admitting such men to the Lodge goes is not clear, but hints of it are discernable in the oldest documents of the order.
Joseph Fort Newton (2013). “The Builders - A Story & Study of Masonry”, p.138, Lulu Press, Inc