In this paper we discuss the nature of artificial intelligence (AI) and present a hexagon of opposition (generalization of the square of opposition) to characterize what intelligence is, its relation with computability, creativity, understanding and undecidability.In a first part, we make some general comments about the history, development and objectives of AI. In a second part, we present two diametrically opposed ways of reasoning, one computational, one creational. In a third part, we talk about the relation between AI and logic, emphasizing that reasoning can be described or/and performed by different logical systems, mentioning the fact that non-monotonic logical systems have been promoted by AI researchers. In a fourth part, we present the theory of oppositions, with the three notions of opposition that are used to build squares and hexagons of opposition, and we then we present a hexagon of intelligence.