What to do after third degree?

Under the settlement of the English Constitution, pure Antient Masonry consists of the three Craft degrees and the Holy Royal Arch, and no more, making the Royal Arch the traditional completion of the Craft system 2. Wilmshurst considers degrees beyond these to be superfluities that risk diffusing a student's attention, holding that the full process of human spiritual regeneration is already outlined within the three degrees and the Royal Arch 2.

For those seeking to explore further, a wide variety of additional degrees elaborate on side points of doctrine or re-express the Craft's teachings 2. Master Masons are eligible for initiation into the Mark Master degree, which in American practice forms the first degree of the Royal Arch Chapter, while in England it is governed by an independent Grand Lodge of Mark Masters 3. Other supplementary bodies open to Master Masons include the Royal Ark Mariner (lodges of which are attached to Mark Lodges), the Secret Monitor, St. Lawrence the Martyr, and the Rose Croix 1. These additional systems range from simple side degrees created primarily for mutual support and fellowship to elaborate, highly symbolic rites 1.