Dualistic thinking, according to William Perry's model of intellectual development, is the intellectual ability to understand good and evil but not the nuances inbetween. He believed it was the base level of intellectual development that most college freshmen possessed.
In dualistic thinking, students rely on authority figures for direction on what is right or wrong. They prefer to memorize and repeat as opposed to analyze and examine, and they are uncomfortable with active and cooperative learning. Facts and figures are comfortable at this level of development; abstract concepts are not.
Perry identified eight levels of intellectual development beyond this one and developed a system, published in 1970, for helping college students grow intellectually well beyond that first level. This framework is an integral part of college teaching today.