General semantics is a school of thought that incorporates philosophic and scientific aspects. Although it does not stand on its own as a separate school of philosophy, a separate science, or an academic discipline, it describes itself as a scientifically empirical approach to cognition and problem solving. It has been described by nonproponents as a self-help system, and it has been criticized as having pseudoscientific aspects, but it has also been favorably viewed by various scientists as a useful set of analytical tools albeit not its own science.

General semantics is concerned with how phenomena (observable events) translate to perceptions, how they are further modified by the names and labels we apply to them, and how we might gain a measure of control over our own cognitive, emotional, and behavioral responses. Proponents characterize general semantics as an antidote to certain kinds of delusional thought patterns in which incomplete and possibly warped mental constructs are projected onto the world and treated as reality itself. Accurate map–territory relations are a central theme.

After partial launches under the names human engineering and humanology, Polish-American originator Alfred Korzybski (1879–1950) fully launched the program as general semantics in 1933 with the publication of Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics.

In Science and Sanity, general semantics is presented as both a theoretical and a practical system whose adoption can reliably alter human behavior in the direction of greater sanity. In the 1947 preface to the third edition of Science and Sanity, Korzybski wrote: "We need not blind ourselves with the old dogma that 'human nature cannot be changed', for we find that it can be changed." While Korzybski considered his program to be empirically based and to strictly follow the scientific method, general semantics has been described as veering into the domain of pseudoscience.

Starting around 1940, university English professor S. I. Hayakawa (1906–1992), speech professor Wendell Johnson, speech professor Irving J. Lee, and others assembled elements of general semantics into a package suitable for incorporation into mainstream communications curricula. The Institute of General Semantics, which Korzybski and co-workers founded in 1938, continues today. General semantics as a movement has waned considerably since the 1950s, although many of its ideas live on in other movements, such as media literacy, neuro-linguistic programming and rational emotive behavior therapy.

In the 1946 "Silent and Verbal Levels" diagram, the arrows and boxes denote ordered stages in human neuro-evaluative processing that happens in an instant. Although newer knowledge in biology has more sharply defined what the text in these 1946 boxes labels "electro-colloidal", the diagram remains, as Korzybski wrote in his last published paper in 1950, "satisfactory for our purpose of explaining briefly the most general and important points". General semantics postulates that most people "identify," or fail to differentiate the serial stages or "levels" within their own neuro-evaluative processing. "Most people," Korzybski wrote, "identify in value levels I, II, III, and IV and react as if our verbalizations about the first three levels were 'it.' Whatever we may say something 'is' obviously is not the 'something' on the silent levels."

By making it a 'mental' habit to find and keep one's bearings among the ordered stages, general semantics training seeks to sharpen internal orientation much as a GPS device may sharpen external orientation. Once trained, general semanticists affirm, a person will act, respond, and make decisions more appropriate to any given set of happenings. Although producing saliva constitutes an appropriate response when lemon juice drips onto the tongue, a person has inappropriately identified when an imagined lemon or the word "l–e–m–o–n" triggers a salivation response.

"Once we differentiate, differentiation becomes the denial of identity," Korzybski wrote in Science and Sanity. "Once we discriminate among the objective and verbal levels, we learn 'silence' on the unspeakable objective levels, and so introduce a most beneficial neurological 'delay'—engage the cortex to perform its natural function." British-American philosopher Max Black, an influential critic of general semantics, called this neurological delay the "central aim" of general semantics training, "so that in responding to verbal or nonverbal stimuli, we are aware of what it is that we are doing".