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could be considered a paradox. "Constructive" implies the intention of advancing a good purpose or to provide help. Conversely, "criticism" (of course) suggests that an individual or item is being judged severely, and the feedback returned in a harsh manner. Cons ....

Middle of Essay
.... criticism helps to improve the accuracy and quality of choices made for the nation by our elected officials. Found in some form in nearly every aspect of our society, constructive criticism is an indispensable facet of human improvement. The vast majority of ideas and behavioral characteristics can be improved, often quite substantially, by a different individual who possesses a contrasting perspective. Every human is unique, and has ideas indigenous to his personality and experience. A contrasting point of view can often be used to provide legitimate, constructive input more effectively than could an individual with a similar perspective. ....