Dissociation: Pierre Janet's vision

I emphasize the importance of knowing the origins of the concept of Dissociation in Pierre Janet's perspective, given its current applications in the study and treatment of trauma and Post Traumatic Stress Disorder, among other similar topics. The main objective of this review is to explain, from Janet's view, the concept of Dissociation in relation to: "Fixed Ideas"; "Narrowing of the Field of Consciousness" and "Weakness of Mental Synthesis". I describe the Functional Neurological Symptoms and Amnesias, denominated in her time as Hysteria, from where the concept of Dissociation arises in part, describing the diagnosis of the Hysterical symptom as opposed to the organic symptom. I try to condense what is referred to in the following definition: "Dissociation is the loss of synthesis and association of the psychological functions, which move away from the Consciousness and are relegated to the Subconscious, situations that occur due to an Emotional State or spontaneously, this allows to move away from the Consciousness that State, which is represented in various symptoms".