I honestly do not believe quantum mechanics (QM) is first principles enough, in the philosophical sense. QM deals with probabilites and unstrapped the desire (or at least is currently incapable as of now) of aiming to describe the particle behavior and motion of small particles and systems and their interactions. Rather it tries to justify its current inabilities to understand actual particle dynamics because the excuse is that statistical means as an 'best alternative' is actually sufficient.
However, physics in general, philosophically can only do so much as to describe natures laws because physics is surposed to define the most fundamental and the idea of 'facts' is much harder, if ever possible to achieve in physics, than in other subjects in which concrete proofs and 'facts' may be achievable. But in physics the idea of first principles is the use of the most fundamental laws to describe nature's responses, and QM fails to do this because it fails on being able to describe particle dynamics in which to correlate the QM current findings (e.g. probability desnity of particles), etc.
Wt do you think.