(Quote) Gareth Knight - A Practical Guide to Qabalistic Symbolism, Pt 1

"Esoteric psychology teaches that when an entity such as man comes into incarnation the relatively immortal part of himself variously called the Higher Self, Evolutionary Self, the Soul etc. ~ projects a rod or thread-like process into the lower levels which forms the basis of personality, and this develops a life of its own and is kept alive by means of this life thread which has been described a 'silver cord' not only in the Bible but also in recorded experiences of etheric projection, the details of which are available in many books on psychical research. As the personality develops towards maturity the Higher Self begins to take over to a greater or usually lesser extent and this is by means of opening up the thread of consciousness between the two levels of being.
The aim of esoteric training is to make this dual consciousness a single reality. The consciousness of the Lower Self is raised by means of meditation, contemplation, and prayer and the Higher Self is brought down by attention, intention and, in the West, ritual methods."