The nervous system consists of the central and peripheral nervous systems. Most physiological functions are autonomic not under conscious cortical control. Human behavior can be explained by the inner self (nafs), organic factors (chemical and anatomical), early learning, early conditioning, and socialization. Genetically-determined organic factors of behavior do not excuse humans from accountability because the inner self (nafs) can override organic factors. Diet and environmental factors may also affect behavior. Humans can artificially change their behavior by using chemicals and intoxicants.

THE INTELLECTUAL FUNCTION, ‘aql

Intellect, ‘aql, includes conceptualisation and categorization, measuring and counting, concrete and abstract thought, causal reasoning, and problem solving. It cannot reason out all moral issues without guidance from revelation. Human intellect is very creative and imaginative. It is the basis of judgment (reconciling apparently contradictory information). It is needed for sensory perception. It is needed for acquisition of knowledge. It is related to observation. The 3 main intellectual processes are understanding (fahm); insight (idraak) and judgment (hukm). Consciousness (shu’ur), is both physical (awareness of the environment) and moral (sensitivity to immoralities in the community). Learning is related to memory and language. Humans think by manipulating verbal symbols. Communication is the basis for growth of civilization, family and social functioning, problem solving, and acquisition of new knowledge.

MEMORY FUNCTIONS, hifdh

Humans are capable of great memory but the capacity is not fully used. Short-term memory is recollection of recent events. Long-term is persistent recollection of distant events. Implicit memory is involved skills such as driving, eating, and drinking. There is a neurological basis for memory. Memory capacity can be enhanced by prayer (dua), strong motivation, and repetition. Memory can suffer from decay, distortion, confabulation, moral forgetting and physical forgetting. Forgetting as a type of negligence. Humans are not punished for forgetting. Reminding in a moral sense and the physical sense helps humans remember.

THE MOTIONAL FUNCTION