This paper posits Peirce’s logical category of abduction as a necessary component in the learning process. Because of the cardinality of categories, Thirdness always contains in itself the Firstness of abduction. In psychological terms, abduction can be interpreted as intuition or insight. The paper suggests that abduction can be modeled as a vector on a complex plane. Such geometrical interpretation of the triadic sign helps to clarify the paradox of new knowledge that haunted us since Plato first articulated it in (...) his Meno dialogue. Some implications for the actual teaching practice are addressed, and the value of practical knowledge affirmed. (shrink)