Even though we shall distance ourselves completely from these two
approximations, we shall adhere to the above-mentioned principle in
order to make gravitation comprehensible. This means that we shall
bring the Eotvos property into the purview of quantum mechanics by
insisting that we find a carrier of the imprints of gravitation which
is *both* independent of the intrinsic mass of the carrier, *and*
is purely quantum mechanical in nature.

This requirement turns out to be extremely restrictive, but not overly so.

In quantum mechanics, unlike in classical mechanics, the dynamics of a system is an issue separate from the measurement of its properties. Consequently, our formulation comes in two parts. There is the mathematical part which develops the dynamics of the carrier, and there is the physical part which describes how to measure the gravitational imprints with physically realizable apparatus. In this article we shall consider primarily the first part. A key aspect of the second is pointed out in the concluding section, while a more extensive sketch has been consigned to another article. [9].