Mental energy or psychic energy is the concept that there is a principle of activity behind the operation of the mind or psyche. Just as physical energy acts upon physical objects, psychological energy would act upon psychological entities, i.e. thoughts and feelings. Psychological energy and force are the basis of an attempt to formulate a scientific theory according to which psychological phenomena would be subject to precise laws akin to how physical objects are subject to Newton's laws. This concept of psychological energy is completely separate and distinct from (or even opposed to) the mystical eastern concept of spiritual energy.