Long ago, in a country that speaks Latin, there were two siblings, ‘a priori’, a girl, (nicknamed ‘pri’) and ‘a posteriori’, her brother (nicknamed ‘post’). Pri would only ever speak of things that she had no experience of, and Post only ever spoke of things he had experienced. They argued all the time, Pri used deductive logic and knew that things were so, because she reasoned it out, while Post used inductive logic, and only knew things like, you get burnt if you put your hand into the flames of a fire, because he had tried it. He had many burns and scars from trying things out. Of course, Pri had no scars or past injuries, because she had used logic such as; fire is hot; fire cooks meat; cooked meat is softer than raw meat and more easily chewed; therefore meat is changed by heat. She also knew that if she got really hungry she could cook and eat her brother. Post, however, did not know this and was therefore not afraid of Pri, his sister. Because Pri knew that her brother could never know that his sister was potentially food, without having eaten her first, she was also not afraid.
In reality, someone who never uses empirical knowledge would never learn that heat cooks meat and maked its more chewable and so more digestible, and they certainly would never learn to eat or communicate.
a priori and a posteriori
a priori knowledge is independent from any experience
a posteriori knowledge depends on empirical knowledge
Converse to the roles played by the characters above: In the Bible, in the Garden of Eden, Eve eats fruit from the tree of knowledge. This is not a normal tree of knowledge. Its fruit embues (sic) ‘knowledge attained through experience’ to the eater. Suddenly, Eve had experiential knowledge, whereas Adam, had only knowledge based on definitions and first principles. In almost any bipartisan relationship, I suggest, where one partner has experience and the other does not, there exists an unfillable gap; a chasm that continues to grow between the pair. The obvious solution is for Adam to also eat from the tree of knowledge. Yet, it was Adam’s remit to follow doctrine and not make up reasons for doing things simply because he knew how good it felt to do those things. But, Eve, the minx, got Adam addicted to pleasure, the naughty girl. Yes, you guessed it, it is because of Eve that y’all have SmartPhones, and are addicted to dopamine. The canny people out there also realise that without Eve none of us would get invited to parties. Go Eve!
In a court of law, like any place where decisions are made that determine how someone’s life will continue to unfold or exist, ‘a priori’ arguments appear to be cold and immutable. Mathematics uses ‘a priori’ analysis, as do scientists. Engineers, on the other hand, use ‘a posteriori’ analysis; inductive logic, which comes from observational evidence. That is not to say that they do not also use ‘a priori’ arguments or logic; it simply means they solve problems in the real world with workable solutions. I once overheard a welder complaining that a computer told him to bend a sheet of steel in three dimensions.
Let
us imagine an early settlement of 500 people that is separated by a
fast-flowing river from another settlement with a enticing and attractive market. It is
essential to the person who uses only ‘a priori’ analysis that a
toll-bridge must be built at the narrowest point of the river, which
is half a mile north of the settlement. To this person, the cost of
the bridge, being the wages for lumberjacks and engineer-type
carpenters, must be recovered from the users of the bridge. To a
person who has experience of the bears in the woods half a mile
north, the sensible place to cross the river is closest to the
settlements. This person, who has used 'a posteriori' knowledge, becomes
a ferryman and charges the same as the toll for the bridge, and
because there were no set-up costs to recover, makes so much money he
builds a monument, in the village square, mocking ‘clever’
people. (Your mission, should you choose to accept it, is to come up with a way for the 'clever' people to get their revenge on the ferryman).
People use both these types of reasoning, and in any scenario there will be characters who dwell, even for shorts periods of time, in one or the other camps of decision-making. These types of thinking are used before and after education or experience.
prior – before, in front, ‘previous’
posterior – later, after, inferior ‘behind’
A priori and a posteriori
From Wikipedia: 'A priori and a posteriori are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on experience. A priori knowledge is independent from any experience. Examples include mathematics, tautologies and deduction from pure reason. A posteriori knowledge depends on empirical evidence.'
Prior analytics (a priori) is about deductive logic, which comes from definitions and first principles.
Posterior analytics (a posteriori) is about inductive logic, which comes from educational and empirical evidence.
Deductive reasoning
This involves starting from a set of general premises and then drawing a specific conclusion that contains no more information then the premises themselves. (dictionary.com 2021)
Inductive reasoning
Inductive is a way to describe something that leads to something else, so when applied to reasoning it just means you collect information and draw conclusions from what you observe. (vocabulary.com)
Roget’s Thesaurus helpfully offers ‘subtract’ as a near synonym for ‘deduct’. If we deduct four coins from these six coins, how many do we have?
Roget’s
Thesaurus also helpfully offers ‘cause’ and ‘influence’ as
near synonyms for ‘induce’. We can induce someone to believe
something. In physics, electro-magnetic induction is causing
electricity to flow by changing or altering magnetic fields.
Making sense of the world by imaging other worlds
For those people who like to write their own stories and develop characters to understand their own world around them: when someone makes an abrupt change from one way of thinking to another, it can be discombobulating to the persons they are with, or who are observing that person. We all use both deductive and inductive reasoning, yet the extent to which we dwell in each camp determines who we get on with. This is not much different to people who have been trained in convergent making decisions about people who evince no training in convergent thinking. Essentially, if you have ever felt as though you have been ‘pigeon-holed’ or heard someone say that they have been ‘pigeon-holed’ [1], you have just observed the victim of someone else using convergent thinking to assess the needs or circumstance of others. People with low mental health; that is all of us at some point in our lives, tend to use divergent thinking during our episodes of illness. Divergent thinking is used for creativity. So, if you have just been dumped by your boyfriend or girlfriend, you will likely make up stuff in your head, like, that person was the love of your life, if you didn’t think that before. Convergent thinking is used for writing essays and reports, and Divergent thinking is used for creativity.
Ultimately though, there has to be a merging of these thinking styles if you are planning on learning from your experiences and sharing them. That is to say: there has to be structure and sadly, robust pruning of the fun and creative playground we once dwelt in as children to become, as adults, a figurative fenced-off imagination. I propose that it is the liminal space (at the invisible fence) that story-tellers spend their richest time: the threshold between order and chaos. Great film-makers use our ability to access our experiences by showing us where the fence between order and creativity exists. The film has a plot (order) but is believable because the characters are creatively formed. A murder mystery must have someone with a motive, for example.
1 Pigeon-holing means to classify entities into categories, often with negative connotations – Wikipedia https://en.wikipedia.org › wiki › Pigeonholing
References
dictionary.com (2021), Available at: https://www.dictionary.com › e › inductive-vs-deductive
vocabulary.com, Available at: https://www.vocabulary.com/dictionary/inductive