Searching for evidence of critical thinking in discourse has roots in a definition of critical thinking put forth by Kuhn (1991),  which places more emphasis on the social nature of discussion and knowledge construction. There is limited research on the role of social experience in critical thinking development, but there is some evidence to suggest it is an important factor. For example, research has shown that 3- to 4-year-old children can discern, to some extent, the differential creditability  and expertise  of individuals. Further evidence for the impact of social experience on the development of critical thinking skills comes from work that found that 6- to 7-year-olds from China have similar levels of skepticism to 10- and 11-year-olds in the United States.  If the development of critical thinking skills was solely due to maturation, it is unlikely we would see such dramatic differences across cultures.
Barzun’s critique of the cult of evolutionary theory and the canonisation of Darwin himself is impressive but it is difficult to identify where Barzun stands on the scientific status of evolutionary theory and this is the least convincing part of his work. He appears to be dissatisfied with materialism and determinism without explaining whether he adhered to vitalism, or some form of mysticism or religion. This underlines the problem of pursuing such a wide-ranging research project without the assistance of co-workers, so his reach may have exceeded his grasp at some points. This is especially apparent when he attempted to locate his work in the context of twentieth century physics and biology, where he was operating too far from his base in history and cultural studies.
To further clarify the Creative Commons license related to the 20 Critical Controls content, (i) All persons are authorized to use the content as a framework in their organization or to sell professional services related to the content (. a consulting engagement to implement the 20 Critical Controls), and (ii) sale of the contents as a framework model is not authorized. Users of the 20 Critical Controls framework are also required to refer to http:///critical-security-controls/ when referring to the 20 Critical Controls in order to ensure that users are employing the most up to date guidance.