Each of the five senses functions as a communicator between the external environment and internal receptors. This communication reflects a cause-effect approach; the information an individual perceives from their senses causes a distinctive bodily response. Without persistence in recognizing external changes in the environment, life would not thrive. Imagine waking up unable to see, smell, taste, hear, or touch. While the lack of one meaning produced a heightened sensation in the other four, the lack of more than one meaning decreased the quality of life. As the book makes clear, the senses reflect a window on the environment and a thermostat on internal needs. It remains essential 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 needed to communicate them