Most of work on reasoning and decision-making in virtual agents relates the choices with a exhaustive exploration, analyzing every possible alternative and implication, and trying to maximize some utility measure in order to make the best decision. Humans, however, seems no reason and make decisions naturally in this way. As authors such as Herbert A. Simon have proposed, humans seems to develop a concept of bounded rationality, according to which human reasoning process and decision-making is bounded to a part of reality at a time as a focussing effect. According some psychologists, focus of thought is one of the main purposes of emotions in humans. Using an abstract framework, in this work we propose an approach to consider emotions as an argument-selection heuristic towards the ability for an agent to reason and act in a believable manner. Influenced by emotions, the agent will produce a line of reasoning according to the evolution of its own emotional state.