The language of smells is primarily an animal language, yet it is also part of the human signaling system. In the previous chapter, we established that there is still no universally accepted classification of odors. One reason for this is that humans lack an abstract concept of smell. The olfaction specialist A. Bronstein states: “While we have the notions of salty, sour, sweet, and bitter for taste—terms that describe properties of many substances—and for colors the notions of blue, green, yellow, and other colors, which are characteristic of many objects, our ideas about smells are object-oriented. We cannot characterize a smell without naming the substance or object to which it refers.” It is the concreteness of the information associated with smells that leads animals to trust their sense of smell. A dog may not recognize another by its voice or appearance and may start barking, but its behavior changes as soon as it smells the other. The individual scent is the most reliable attribute for identifying its owner. That is why the human saying “I only trust my eyes!” in the language of dogs becomes “I only trust my nose!”