Various writers have recently emphasised the intelligence of some animals, the intentionality that characterises many of their actions, and other features that show the affinity between their mentality and action and ours. While granting these observations, I try to identify elements of our mental capacities which separate us from animals. I focus on our command of logical concepts, demonstrable already in children in the second or third year of their life, which to date no animal has been shown to master. I draw various conclusions about behavioural, emotional, and moral capacities dependent on such mastery, and discuss recent empirical work which supports the claim that animals, even those we consider intelligent, are limited in these respects.