Definitions: (1) directly producing the desired result with a minimum of effort, expense, or waste; (2) working at optimum proficiency; (3) wise progress; competent; capable
     See also: Effective

Synonyms: able, causative

Consequential Quality: Self-efficacy: (1) To believe in one’s own abilities to accomplish a goal; (2) the aptitude to deal with the stresses involved in facing specific difficulties; (3) understanding and accurately judging the inherent risks of an objective; (4) The clarity of knowing when the job is done well enough
     Note: A perfectionist can always see another decimal point to nudge the project just that closer to perfection.

Quote: Just think of the advantage that the first warm-blooded mammal would have had at night, all the reptiles cooled down to somnolence unable to defend themselves. And all because of an abnormally inefficient animal (by cold-blooded standards!) that wasted energy by metabolizing food when it wasn’t needed for movement. But this kept body temperature up and so the animal was pleasantly surprised by all the sleepy prey he encountered, which more than made up for all the wasted energy. The next time that you hear an evolutionary argument based on efficiency, remember those profligate warm-blooded animals. — William H. Calvin (1939-) American theoretical neurophysiologist; The River That Flows Uphill {1986}