In Slavin (2009): "In Maslow's theory, needs that are lower in this hierarchy must be at least partially satisfied before a person will try to satisfy higher-level needs" (p. 299).

"Deficiency needs (physiological, safety, love, and esteem) are those that are critical to physical and psychological well-being; these needs must be satisfied, but once they are, a person's motivation to satisfy them diminishes. In contrast, growth needs, such as the need to know and understand things, to appreciate beauty, or to grow and develop in appreciation of others, can never be satisfied completely" (p. 299).

"The importance of Maslow's theory for education is in the relationship between deficiency needs and growth needs" (p. 300).

Visit the Wikipedia article for an image of Maslow's hierarchy of needs.