Emotional participation in decision making. The results of recent neurophysiological and neuropsychological research make it necesary to take into account participation of emotions in decision processes. The amygdala, that has revealed itself as a structure capable of asigning emotional meaning to environmental stimuli (evaluation), originates a series of reactions that include motor, autonomic, endocrine and central nervous system adaptations (emotional expression). All these changes also feed back on brain, giving rise to what is known as emotional experience or feelings. On other hand, neuropsychological research has demonstrated importance of prefrontal cortex in decision making, showing an intimate cooperation of emotional limbic mechanisms with anticipating and planning functions of prefrontal cortex. (The somatic-marker hypothesis of Damasio is exposed). Neurobiology is thus confirming what Pascal intuitively expressed when writing that the heart has reasons that reason ignores.