and key properties that characterized these states. The emotions which Heider had a particular interest in are those which are considered interpersonal such as: anger and vengeance, sorrow and pity, gratitude, love, envy and jealousy. Heider primarily argued that in cases where one’s fundamental logic appears to be contradicted by something else, a much fuller analysis of the particular situation must take place. In relation to anger, Heider’s notes consider cases in which a violated “ought” was to be a critical component in the arousal of anger and then follow an observation of the emotional reaction produced once that component is met. He notes how anger and annoyance create a paradox when someone feels social pressure to do what they know they “ought” to do. Heider considers this a paradox because within his general theory of balance, two forces acting in agreement should form a balanced structure and balanced structures should in turn produce positive rather than negative effects. Force one is social pressure and force two is the “ought” force, which both act in the same direction. The direction of the two forces should create harmony but in turn they create the opposite. Heider noted that the feeling of violation, particular to that of a violated “ought”, was a cognitive antecedent that characterized angered states. However, he also noted that cognition does not always seem to be a necessary condition for producing anger. In relation to gratitude, Heider also points out necessary antecedents. He states that gratitude depends not only on receiving help but also on the perception of the intent of the help received as well as the perceived reason for the positive intent which has the power to modify and influence the causal attribution. Heider mentions that the need for one to maintain balanced states can affect the experience of gratitude as well as other emotions. In his notebook, he raises the question of why someone might be hesitant to accept a gift from a hated individual and later goes on to explain how one would rather keep the hatred felt toward the individual than have to mix it up with gratitude. In addition to the work mentioned above, Heider explains how there seems to be some cognitive schema that has both a general and pervasive influence which led to the simplification of perception. In his notebook, Heider explains how people have a tendency to believe in