Amazon.com description: Product Description: In a similar way the definite reaction to the word 'steepness' grows up. The lad takes a walk with his mother over stretches where there are no paths. When he goes up a hill he pants and blows and sweats. His mother says, "Steep, isn't it?" Steep becomes substitutable for panting and blowing and sweating. They come to another hill. The mother says "Steep, isn't it? You are tired; let's go round." He learns by trial and error that the word steep is followed by sweating, hard work and tired limbs and that this exertion can be avoided by turning to the right or left and circling instead of keeping straight on.