Bill Barnes suggested it might be possible to simplify the 7th law to this:
The unifying identity metasystem must make it easy for humans to make fully informed identity choices in the course of interacting with relying parties.
I see this as an important practical corollary of the law. But the law implies more.
First, we need a system in which different identities (and kinds of identities) are reified (represented as “things”) in a consistent way, so the user can easily conceptualize and enumerate different identities, and select the right one for a given context. So from the point of view of the user the identities need to represent a harmonious set.
Second, the relying party should be able to switch between different kinds of identities as needed with no technical or programming overhead, even if the identities are based on completely different technical systems and tokens – so from the point of view of the relying party, the identities again constitute a harmonious set
Thus we say:
The unifying identity metasystem MUST facilitate negotiation between a relying party and user of a specific identity – presenting a harmonious human and technical interface while permitting the autonomy of identity in different contexts.