  Starting from a new principle inspired by quantum tomography rather than from
Born's rule, this paper gives a self-contained deductive approach to quantum
mechanics and quantum measurement. A suggestive notion for what constitutes a
quantum detector and for the behavior of its responses leads to a logically
impeccable definition of measurement. Applications to measurement schemes for
optical states, position measurements and particle tracks demonstrate the
applicability to complex realistic experiments without any idealization.
  The various forms of quantum tomography for quantum states, quantum
detectors, quantum processes, and quantum instruments are discussed. The
traditional dynamical and spectral properties of quantum mechanics are derived
from a continuum limit of quantum processes, giving the Lindblad equation for
the density operator of a mixing quantum system and the Schr\"odinger equation
for the state vector of a pure, nonmixing quantum system. Normalized density
operators are shown to play the role of quantum phase space variables, in
complete analogy to the classical phase space variables position and momentum.
A slight idealization of the measurement process leads to the notion of quantum
fields, whose smeared quantum expectations emerge as reproducible properties of
regions of space accessible to measurements.
  The new approach is closer to actual practice than the traditional
foundations. It is more general, and therefore more powerful. It is simpler and
less technical than the traditional approach, and the standard tools of quantum
mechanics are not difficult to derive. This makes the new approach suitable for
introductory courses on quantum mechanics.
  A variety of quotes from the literature illuminate the formal exposition with
historical and philosophical aspects.
