  A detailed and updated review is given of De Filippo's Non-unitary $4$-th
Derivative Gravity and its Newtonian limit, by pointing out the crucial role of
non-unitarity in addressing transition to classicality and specifically
localization of macroscopic bodies, microscopic foundation of the second law of
thermodynamics, measurement problem; furthermore it provides a quantum field
theory of gravity possibly not only renormalizable but even finite, with a
cancelation mechanism analogous to supersymmetric field theories where
cancelations are due to superpartners whereas here to negative energy fields.
Finally this non-unitary proposal addresses the longstanding black hole
information loss problem and this according to an unorthodox view at variance
with the mainstream endeavors to save unitarity at the expense of changing
General Relativity in vague unspecified ways. Last but not least motivations
and conceptual framework are given, as the author could not present them in his
first papers written in a hurry since he was aware that in a little time he
would be unable to use pc keyboard or to write on paper due to the progressing
of motor neuron disease.
