Key reason ideas

Key reason ideas

These key reason ideas will help you to understand theory of knowledge, and produce a powerful TOK essay and presentation. You should try to the terms as much as possible, and ideally link them to key TOK thinkers.

Barnum statements

A Barnum statement (also known as the ‘Forer Effect’) is the term given to a statement about a person that they believe correctly describes them – such as a horoscope or ‘psychic reading’ – but which is, in fact, a general description that could apply to almost anyone. Meaning and sense is projected into the statement by the person reading it, rather than the statement being based on any real knowledge.

Blanket terminology

Blanket terminology is the name given to a term that assigns the same name to a range of often unrelated or disparate group of events, phenomena, or ideas. It is found most commonly in history, in which historical eras and long periods of time are assigned a name which tendentiously lends the impression of continuity. One such example is the ‘Cold War’.


The causation of a phenomenon is what directly makes it occur. This is in distinct contrast to correlation, in which two phenomena are linked only by a third factor, or by accident.

Cold readings

Cold readings are employed by self-styled psychics in order to make their clients believe that they possesses the ability to contact the dead, or perform supernatural tasks. Such individuals use existing knowledge of the person they are ‘reading’, linguistic tricks, and hints from the subject’s appearance and body language in order to conjure up information about them that it seems impossible for them to know. They make extensive use of Barnum statements.


Unlike causation, correlation suggests that two events or phenomena are linked only because they both share a third factor, or simply because they have happened at the same or similar time.


Deduction is a form of reasoning in which you go from a general rule to a specific rule. If you use deduction strictly, it gives you certain knowledge.


Induction is a form of reasoning in which you go from a specific rule to a general rule. Unlike deduction, induction never gives us certain knowledge, unless you are dealing with mathematics.

Lateral thinking

Lateral thinking, a phrase coined by Edward de Bono, means thinking creatively and sometimes in an unorthodox manner, to arrive at a solution about a problem. It means the same as ‘thinking out of the box’.


Logic is formal reasoning, or reasoning that follows strict rules (in contrast to ‘lateral thinking’).

Logical fallacies

A logical fallacy is an idea or assertion that uses flawed reasoning to arrive at its conclusion. Fallacies may occur by accident, or be used by people deliberately to persuade others of the dubious truth of what they are saying.


Nationalism is the emotionally-based belief that humans should be defined by the political entity in which they live, and that their allegiance should lie first and foremost to the government and people of that place. It often assumes a superiority of one’s own nation in comparison to others, and can act as a psychological bias when it comes to a study of history, human sciences, and other areas of knowledge.


A pseudo-science is a discipline that may claim to follow the scientific method, but which does not do so in a strict way. Its results are therefore not as objective or reliable as a true science.


Reason is a word with a huge amount of meanings, but in TOK we understand it to be the way of knowing which involves us in trying to make sense of the world using logic, rationality, comparison, judgement, and experience.

Somatic marker hypothesis

The somatic marker hypothesis is a hypothesis put forward by the neuroscientist Antonio Damasio. It proposes that emotional experiences we have in our lives leave a chemical trace behind in our brain, and these chemicals are unconsciously accessed when we are faced with a similar event again, helping us to find a resolution.


Stoicism was a Hellenistic (ancient Greek) philosophical movement that massively influenced the early Christian religion. It is based on many principles, but one of the central ones is that the effects of damaging emotions can be overcome simply by refusing to view them as damaging, focusing instead on reasoning to arrive at the truth. Important Stoic thinkers include Marcus Aurelius, Epictetus and Seneca.


Superstition is either discerning a pattern in the natural world when there isn’t one, or not discerning a pattern when there is one, and then ascribing such a phenomenon to an entity ungoverned by the laws of nature.


A syllogism is an example of a logical argument in which two premises lead to a conclusion. If syllogisms use correct premises, their conclusion must always be valid. One of the most famous syllogism goes like this:

Premise 1: All men are human
Premise 2: Socrates was a man
Conclusion: Socrates was human


Ways of knowing

The TOK course is divided into eight ways of knowing: emotion, faith, imagination, intuition, language, memory, reason, and sense perception. These ways of knowing are how we gather our knowledge about the world.

Cite this page as: Dunn, Michael. Key reason ideas (21st August 2014). Last accessed: 20th March 2018


Leave a Comment