 Physicalist and neutral monist varieties of Russellian monism are most naturally understood as forms of Russellian panprotopsychism, whereas idealist and dualist varieties are most naturally understood as forms of Russellian panpsychism (but see Schneider 2018). Much of the recent literature on Russellian monism focuses on the physicalist variety, often called Russellian physicalism (Montero 2015). Russellian physicalism is usually presented as an alternative to, rather than a version of, traditional physicalism. But that might seem misleading. On many traditional physicalist theories, there are non-phenomenal properties that can collectively constitute phenomenal properties, perhaps when arranged in the right structure—microphysical properties, say. On those theories, such properties would qualify as protophenomenal properties by the characterization quoted above from Chalmers 2013 (Papineau 2002: 22–23, fn. 5).