Originally published in 1963, this is a classic work on the psychology of perception. By means of suitable patterns on a partly concealed rotating disc Michotte was able to give the impression of objects in movement; and where certain conditions of speed, position, and time-interval were satisfied, his subjects received the impression of a causal interaction between two objects - for example, the impression that one object has 'bumped into' another (the 'Launching Effect') or is carrying it along (the 'Entraining Effect'). In a further group of experiments Michotte studies the conditions in...