The document discusses various aspects of thinking including:
1. There are several types of thinking such as perceptual, conceptual, reflective, creative, critical, logical, and non-directed thinking.
2. Thinking involves problem solving and use of symbols. It can be concrete, abstract, implicit or explicit.
3. Jean Piaget's stages of cognitive development include sensory-motor, pre-operational, concrete operational, and formal operational stages.
4. Development of thinking involves adequate knowledge, motivation, freedom, incubation, intelligence, language development, and reasoning skills.