Glimpsing at guessing

This paper just tries to present a new way to look at Commonsense Reasoning, at the end a manifestation of the natural phenomenon ‘thinking’, and, perhaps, the only skill human beings truly share for their survival. Since imprecision is pervasive in Commonsense Reasoning, the development of what is presented is done with fuzzy sets endowed with a very loose structure, is centered on the concepts of conjecture and refutation, allows to define not only informal and formal consequences, but hypotheses and speculations, and, specially, creative speculations. The study of Commonsense Reasoning is one for which researchers cannot be blind by believing that it is just a logical or mathematical subject. It is much more.