For five hundred years, Western man has turned his energies outward. By far the most creative and universal invention in the period was the development of objective, explanatory, specialized sciences by Galileo and Newton.
The Galilean/Newtonian natural philosophy gradually spread, to chemistry and geology in the 18th Century, to biology and archaeology in the 19th Century and to psychical research in the 20th.
Psychical research is in no way different in its methods from physics. It lends to the comprehensive outer theory of occultism, simply called "Psychonics."
This empirical/theoretical development shows the mind has its own channels of information into past and future, the far away and hidden, and into the ultimate nature of things.
Thus, outer experience paves the way for inner experience.