Each of the five senses functions as a communicator between the external environment and internal receptors. This communication reflects a cause and effect approach; the information an individual perceives from their senses causes a distinctive bodily response. Without the persistent recognition of external, environmental changes, life would not thrive. Imagine waking up unable to see, smell, taste, hear or touch. Although the absence of one sense produced increased sensation in the other four, the absence of more than one sense decreased quality of life. As the book explains, the senses are a window to the environment and a thermostat to internal needs. It remains imperative to understand how the senses communicate not only with external changes, but also with internal needs. Without the ability to physically observe internal needs, a mechanism is necessary to communicate one's needs.