This paper deals with human being by analyzing the relationship between his sensory and rational nature through the written legacy of Thomas Aquinas. The aim of this paper is to analyze how passions shape human being and his life activities. The first part of the paper describes the processes of both sensory and rational human cognition. The elaboration of cognition is followed by the analysis of human sensory and rational appetite which, with regard to the object, are essentially connected with cognition, considering that cognition is precondition for appetite. The central part in this paper deals with the topic of passion and includes the definition of passions, the morality of passions and a description of the order between concupiscible and irascibile passions, but also includes a description of the individual passions in Thomas' thought. Particular attention is given to love, hate, concupiscience, pleasure, pain, hope, despair, fear, daring and anger, respectively those passions that Thomas discusses individually. In confering about the passions listed here, their main features are outlined as well as their causes and effects.