 Object permanence. In the last 35 years, the baby’s representation of objects has been re-explored with striking results. A landmark study (Baillargeon et al. 1985) used the violation-of-expectancy paradigm to test the Piagetian claim that infants lack object permanence. Five-month-old infants were shown a screen that rotated 180 degrees up from the surface of a table and back again to its initial position. In the habituation phase, the babies got used to the screen motion and their looking time decreased, evidence that they no longer found the screen’s movement to be novel. In the test phase, an object was placed in the path of the screen as the screen moved downward to the table’s surface. In one outcome, the screen rotated down until it touched the object and then rotated back up to its initial position, an event that adults recognize as possible. In the other outcome, the screen continued its downward trajectory to the table, at first hiding the object and then apparently moving right through the space occupied by the object, an event that adults recognize as physically impossible. The logic here is straightforward: babies will see the second outcome as surprising only if (i) they represent the object as continuing to exist even when it can no longer be seen behind the screen, and (ii) they assume that two objects cannot occupy the same space at the same time. Only then should they look longer at what adults recognize as an impossible event. If, however, young infants lack object permanence or have no constraints about two physical objects occupying the same space, the impossible event will not constitute a violation of any expectation. The results were clear; babies looked longer at the impossible event, indicating that it violated their expectation of objects. The same finding was later demonstrated with 4-month-olds (Baillargeon 1987). These findings offer evidence that very young infants represent objects as persisting even when they are no longer in view, an understanding of object permanence thoroughly at odds with the claims of Piaget and Quine. One may still ask what exactly the child knows or represents (Burge 2010 is especially pertinent here), but the point is that there is something in the child’s cognitive apparatus that is sufficient to generate this expectation, and the burden of explanation is on the view that this is learned from experience. Moreover, these infants also expect that two objects will not occupy the same space at the same time.