  In this paper we are going to introduce a new dynamical postulate in Quantum
Mechanics. This new principle is defined using path integrals over the set of
normalized wave functions. We will show in a qualitative way that this
postulate is equivalent to the Schrodinger equation and to the measurement
postulates. Then we propose a new set of fundamental postulates for Quantum
Mechanics. In this approach to Quantum Mechanics we separate the fundamental
postulates and the physical interpretation. The fundamental postulates are
abstract mathematical principles. Their physical interpretation depend on the
physical system under study. These postulates do not use the concepts of
measurement device and observer.
