255. That basic energy which is symbolised by the lowest step lies at the root of everything in daily life coming under the description of "instinct", and therefore it is called "instinct energy". It has not such penetrating power as the other energies, so that zone where it constitutes the highest factor of consciousness is synonymous with the most primitive zone or plane of existence. Such a zone appears to us in the form of that which we are accustomed to call the "plant kingdom". Therefore, instinct is the highest factor of life or power of consciousness in the plant kingdom.