"The critical act in formulating computational theories turns out to be the discovery of valid constraints on the way the world is structured -- constraints that provide sufficient information to allow the processing to succeed."

“The abstract properties of this mapping are defined precisely, and its appropriateness and adequacy for the task at hand are demonstrated.”

“In order to understand bird flight, we have to understand aerodynamics; only then does the structure of feathers and the different shapes of bird's wings make sense.”

“To understand the relationship between behavior and brain one has to begin by defining the function, or computational goal, of a complete behavior. Only then can a neuroscientist determine how the brain achieves that goal.”

“The primitives of a representation are the most elementary units of shape information available in a representation.”

“Vision is a process that produces from images of the external world a description that is useful to the viewer and not cluttered with irrelevant information.”

“we can experimentally isolate a process and show that it can still work well, then it cannot require complex interaction with other parts of vision and can therefore be understood relatively well on its own.”