Spirit as we now know is the force and energy animating Keely's interetheric realm of matter/energy or ether and proto-ether (interetheric). According to Keely "matter is infinitely divisible". There is no ultimately tiny particle or "God particle" as considered by some but there is an ultimate Neutral Center which more of later. The substance (matter) on these higher and finer realms bears little resemblance to matter on the so-called gross physical 3D realm. Spirit ANIMATES matter either contracting or dispersing. These terms are also well represented by the term "scalar".
Therefore, in Keely's terms cap "S" Spirit is Undifferentiated Mind of the compound Interetheric realm while small "s" spirit is differentiated Mind of the interetheric realm. We will try not to use the term "spirit" as it has too many misleading definitions and connotations. We will endeavor to use Keely's terms which are wrapped in a comprehensive and well thought out paradigm.
"Spirit is a universal essence pervading all nature, even unconscious matter, and manifesting in many ways, such as cohesion, adhesion, etc. It is a Divine, universal, essence-like Soul, but of a lower (vibratory) rate. Spirit essence makes its first material manifestation in the formation of electrons, which enter into the composition of atoms. Soul, as an essence, can manifest only psychically, because of its very high rate of vibration." Dr. H. Spencer Harvey Spencer Lewis, Rosicrucian Order, AMORC
"There is a vast difference between spiritual and soul forces, for, as given, about each force there has been set guards or bounds. Spirit forces are the animation of ALL LIFE giving life-producing forces in animate or inanimate forces. Spiritual elements become corporeal when we speak of the spiritual body in a spiritual entity; then composed of spirit, soul, and superconsciousness...
There is a bit of semantics problem here. When SVP says spirit (small 's') it does not mean God. Small 's' spirit means this animating influence, force and energy. There have been times I've used "Spirit" (cap 'S') meaning God. God means 'creative and all-knowing' which is somewhat different from 'animating' force or influence. Spirit (small 's') animates matter much like electricity animates matter. I would not define spirit in terms of "physical ether". Spirit is as a force and energy flow, condition or state functional (motion causing) within the realm of the Etheric states of matter and energy. The ether is not really a "physical" thing but more like a "liquid light" having properties of both these metaphorical substances. Here are several definitions of ether from Keely and Cayce:
"Truly is there found that the desire must precede the action and that directed thought becomes action in the concrete manner through each force that the spiritual elements manifest through." Cayce (106-9)
"The luminiferous ether - the compound interetheric element - in other words, celestial mind force - is the substance of which all visible (observable) and invisible (non-observable) things are composed." Keely
"The fundamental mode of vibration changes as we reach the fifth subdivision (of matter), to the Dominant, the diatonic third of the mass chord, which controls the vibratory states of both the etheron and interetheron. The awful might concealed in the depths of the Etheric and interetheric subdivisions utterly transcends anything Science has ever known. Even the theoretical energy value of radium now accepted by Science, pales into insignificance in comparison to the energy value of an equal amount of water subdivided to the Etheric or interetheric state." Keely
In this presentation we are dealing primarily with Keely's definition of the ether he developed and used in his lab and his magnificent machines. The definitions used by Cayce and Russell are pretty much the same while definitions from others can be dramatically different. Click here to read the many definitions of ether. So if anyone says the ether does not exist they ought to be asked "Which ether are you referring to?"