The whole gamut of human feelings consists, in essence, of incentives for action, of instantaneous plans to simply cope with life itself, which evolution has transmitted within us. The root of the word ''emotion'', properly speaking (the term emotion, respectively in Latin, is the verb movere: move) seeks mainly to imply that each one's natural tendency to take action is purely inherent. The fact that emotions are leading us to spontaneous acts becomes sufficiently obvious if we notice carefully and painstakingly little children and animals. It is only the ''civilized'' adults, from the whole animal kingdom, the ones who are likely to respond to this striking ''anomaly'', in other words, to see emotions / feelings (i.e. the basic percepts for action) completely detached from their normal reaction. Within the framework of our emotional repertoire, each of the human emotions, without any exception at all, plays a unique role according to what has been revealed about their distinct biological composition. With new methods of penetrating both the human body and brain, researchers are discovering an increasing number of psychological details about how each emotion prepares the human body for a completely different kind of response. In anger's state of mind, the blood flows in our hands and allows us to catch, unfortunately or not, a firearm or to attack an enemy more quickly. The heartbeats increase and an explosion of hormones (like adrenaline) causes a sort of energy so intense that it can lead us into an operational activity. In a state of fear, the blood moves to the large skeletal muscles, for instance, on the legs, which facilitates us to take off at a scuttle or running; therefore, the human face ''becomes pale'', pretending as though the blood is gradually draining (thus, creating the known feeling of ''freezing up from fear''). At the same time, the body literally cools, even briefly, eventually giving us the opportunity to find time to test the seriousness or rather the judicious part of our reaction to escape. The multiple circuits in the brain's emotional centers cause a secretion of hormones that precisely puts the whole body on the alert, making it completely irritable and ready for action, while human attention is focused on the immediate threat so as to better evaluate the desired reaction. One of the main biological changes towards human happiness is the increase of activity in a brain center that specifically inhibits negative emotions, thus increasing the available energy, and also soothes those centers that provoke agitated and upsetting thoughts. Nevertheless, there is no particular change in the biosynthetic state of the human, apart from a general calm that makes the body quickly recovering from the momentary biological upheaval of disturbing emotions. This situation gives the body the proper conditions to rest in general, but also to be significantly armed with any kind of preparation and enthusiasm for any kind of activity, as well as to fight for a wide range of purposes. Feelings of love, tenderness and sexual satisfaction involve the stimulation of the parasympathetic, bio-somatic antipode of activation stimulated by fear and anger, commonly referred to as a ''fight or flight'' reaction. The parasympathetic model, generally known as the ''relaxation reaction'', is a set of bodily reactions that causes a general state of rest and satisfaction, thus facilitating the collaboration between mind and body. Our eyebrows' lifting by surprise allows us to obtain a wider angle of view (or perhaps a ray of light) and thus let a little light to fall on the retina of the eye. This helps to provide more information about the unplanned event, which allows us to better understand what is happening in front of/around us and to decide on the most appropriate course of action. (...) (...)