In constructivism, what a person knows exists in the form of a mental model or framework. When the person communicates, s/he externalizes the contents and "meanings' of this mental model/framework thereby making these contents available to others. In chapter 6, I already show that no mental model has to be available for a person to talk about physical or mathematical phenomena. In this chapter, I extend the analysis by showing and theorizing how thinking itself develops in the process of the articulation of a topic. I draw on university lectures given by professors with decades of experience of lecturing science courses. In the examples we can see that thought develops in articulating itself only to find itself in a contradiction. The idea that has been communicated in the end turns out to be problematic as recognized by the speakers themselves. Why would have a professor communicated a wrong idea? (There is evidence that this was not done on purpose for rhetorical reasons.) A better way of looking at it is that thought itself develops in communication, and communication develops with thought.