P.N. Johnson-Laird, 1 September 1988
When the single-celled organism paramecium bumps into an obstacle, it reverses the power beat of its cilia, backs away, and swims off in a different direction. How natural to suppose that this animalcule forms a representation of the world, determines that it is obstructed, and decides to set another course. When ‘Washoe’, the celebrated chimpanzee who was taught the American Sign Language for the deaf and dumb, saw a duck for the first time, she made the signs for water and bird. How natural to suppose that she knows how to use language creatively. When Mrs Thatcher tells us that making money is no sin, how natural to suppose that she knows what she is talking about. In all of these cases, we treat other living beings much as we treat our next-door neighbours (most of the time): we assume that they are rational agents with beliefs, desires, and mental representations of the world. We adopt what Dan Dennett, the distinguished American philosopher of mind, refers to as the ‘intentional stance’ towards them. His latest collection of papers is a series of ruminations on quite what we are doing.