Tool-use behavior is currently one of the most intriguing and widely debated topics in cognitive neuroscience. Different accounts of our ability to use tools have been proposed. In the first part of the paper we review the most prominent interpretations and suggest that none of these accounts, considered in itself, is sufficient to explain tool use. In the second part of the paper we disentangle three different types of reasoning on tools, characterized by a different distribution of motor and cognitive (...) ingredients. At the conceptual level, these types of reasoning reflect the distinction between three types of abductive inference as they are described in semiotic studies. At the functional level, we suggest that these types of reasoning on tools may correspond to different mental processes, possibly implemented in different regions of the left inferior parietal lobe. This proposal can account for the different interpretations commonly associated with the role of the left parietal cortex in tool use. (shrink)