An analogy used to explain the development of scientific ideas:
"…it was vain to attack the Aristotelian teaching merely at a single point – vain to attempt in one corner of the field to reinterpret motion by the theory of impetus as the Parisian scholastics had done – which was only like filling the gap in one jigsaw puzzle with a piece out of a different jigsaw puzzle altogether. What was needed was a large-scale change of design – the substitution of one highly dovetailed system for another and in a sense it appeared to be the case that the whole Aristotelian synthesis had to be overturned at once."
Herbert Butterfield (1957) The Origins of Modern Science 1300-1800 (New Edition: Revised and enlarged). G. Bell and Sons Ltd., London.
Read examples of scientific analogies
Impetus theory was an attempt to move beyond Aristotle's explanations of motion, but suggesting a projectile is initially given a certain amount of impetus which is exhausted as it proceeds. Many people today hold alternative conceptions of motion which reflect the impetus theory.
Read about conceptions of Newton's first law (inertia)
