While we have a better understanding of the olfactory pathway today, many of the central questions remain unresolved. How do you classify smells and how do you make their perception comparable? (And how do you control the volatile stimulus, its concentration, and its administration in psychophysical studies?) What are the perceptual dimensions of smell? Are there such things as primary odours? How does the brain represent smells? From this perspective, the discovery of how the sense of smell works presents us with an intriguing, yet untold, history of creativity in scientific reasoning.