Original sentence: Although some people believe this form of energy exists, there is no evidence to support this belief that is widely accepted by todays scientific community.Frequently, this mistake is rooted in the confusion between thought as mental activity with physical quanty work.Freud later added the Death drive (also contained in the id) as a second source of mental energy.However, there was an informal theory that thoughts and mental activity were powered by and transported by a form of energy that did not exactly fit into any of the categories of energy known to physics.In The Ego and the Id, Freud defined Libido as the instinct energy or force, contained in what Freud called the Id, the largely unconscious structure of the psyche.Just as physical energy acts upon physical objects, psychological energy would act upon psychological entities.Mental energy has been mistakenly equated with the physical quantity energy.Psychological energy and force form the basis of an attempt to formulate a scientific theory by which  psychological phenomena would be subject to precise laws akin to how physical objects are subject to Newtons laws.Psychological energy is pseudo-energy that sustains the operation of the mind, soul or psyche.That means the physical properties of work and energy cannot be reasonably applied as justification for properties of mental activity.The idea harks back to Aristotle's conception of actus et potentia.Today we understand that mental activity is powered in the physical sense by metobolic energy derived from chemical reactions.While thought may seem like work in a non-scientific way, and thinkers may be paid as workers, the physical meaning of work and energy are entirely inconsistent with use of terms
Edited sentence: Freud later added the Death drive as a second source of mental energy.In The Ego and the Id, Freud argued that the id was the source of the personality's desires, and therefore of the psychic energy that powered the mind.Mental energy has been repeatedly compared to or connected with the physical quantity energy.Mental or psychic energy or  activity is the concept of a principle of activity powering the operation of the mind, soul or psyche.The idea harks back to   Aristotle's conception of actus et potentia