Immediate inference

Obversion

In traditional logic, obversion is a "type of immediate inference in which from a given proposition another proposition is inferred whose subject is the same as the original subject, whose predicate is the contradictory of the original predicate, and whose quality is affirmative if the original proposition's quality was negative and vice versa". The quality of the inferred categorical proposition is changed but the truth value is the same to the original proposition. The immediately inferred proposition is termed the "obverse" of the original proposition, and is a valid form of inference for all types (A, E, I, O) of categorical propositions. In a universal affirmative and a universal negative proposition the subject term and the predicate term are both replaced by their negated counterparts: The universal affirmative ("A" proposition) is obverted to a universal negative ("E" proposition). "All S are P" and "No S are non-P""All cats are animals" and "No cats are non-animals" The universal negative ("E" proposition) is obverted to a universal affirmative ("A" proposition). "No S are P" and "All S are non-P""No cats are friendly" and "All cats are non-friendly" In the particular affirmative the quantity of the subject term remains unchanged, but the predicate term of the inferred proposition negates the complement of the predicate term of the original proposition. The particular affirmative ("I" proposition) is obverted to a particular negative ("O" proposition). "Some S are P" and "Some S are not non-P""Some animals are friendly creatures" and "Some animals are not unfriendly creatures." In the obversion of a particular negative to a particular affirmative the quantity of the subject also remains unchanged, and the predicate term is changed from simple negation to a term of the complementary class. The particular negative ("O") proposition is obverted to a particular affirmative ("I" proposition). "Some S are not P" and "Some S are non-P""Some animals are not friendly creatures" and "Some animals are unfriendly creatures." Note that the truth-value of an original statement is preserved in its resulting obverse form. Because of this, obversion can be used to determine the immediate inferences of all categorical propositions, regardless of quality or quantity. In addition, obversion allows us to navigate through the traditional square of logical opposition by providing a means to proceed from "A" Propositions to "E" Propositions, as well as from "I" Propositions to "O" Propositions, and vice versa. However, although the resulting propositions from obversion are logically equivalent to the original statements in terms of truth-value, they are not semantically equivalent to their original statements in their standard form. (Wikipedia).

Video thumbnail

What is an Injective Function? Definition and Explanation

An explanation to help understand what it means for a function to be injective, also known as one-to-one. The definition of an injection leads us to some important properties of injective functions! Subscribe to see more new math videos! Music: OcularNebula - The Lopez

From playlist Functions

Video thumbnail

What Is Narcissism?

Narcissism is the word we routinely use to describe someone self-satisfied and arrogant. But what do we really mean by the word – and are we applying it correctly? If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/YfXSQO Join our mailing list: http://bit.ly

From playlist SELF

Video thumbnail

What Infidelity Means

Being a victim of infidelity is one of the worst things that can befall us in love. One of the ways to come back from the harrowing experience is to ask what the real meaning of the infidelity might be. If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/yW1

From playlist RELATIONSHIPS

Video thumbnail

Obtsructive jaundice

In today's video we take a look at the common causes of obstructive jaundice and how you should go about investigating these patients.

From playlist Let's talk Surgery

Video thumbnail

Underactive thyroid.mov

An general explanation of the underactive thyroid.

From playlist For Patients

Video thumbnail

The Achievements of Impotence

Impotence has been turned into a major medical problem and diagnosed as a psychological mishap of the first order. But it is also a very intriguing phenomenon that could throw a flattering light on its sufferers. Please subscribe here: http://tinyurl.com/o28mut7 If you like our films take

From playlist RELATIONSHIPS

Video thumbnail

How Can I Be More Normal?

We are – almost all of us – deeply attracted to the idea of being normal. But what if our idea of ‘normal’ isn’t normal? A plea for a broader definition of an important term. If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/ojRR53 Join our mailing list: h

From playlist SELF

Video thumbnail

Loss of Biodiversity

035 - Loss of Biodiversity In this video Paul Andersen explains how biodiversity measures the variety of genes, species, and ecosystems on the planet. Biodiversity provides resources and ecosystem services for humans on the planet. He also explains how biodiversity is decreasing on the

From playlist AP Environmental Science

Video thumbnail

What is Pure OCD?

Pure OCD (Obsessive Compulsive Disorder) is an unfortunate state of mind, which a surprising number of us may suffer from, where certain deeply distressing, intrusive and shocking thoughts refuse to leave us alone. The suggested solution doesn't target the thoughts themselves, but rather t

From playlist SELF

Video thumbnail

Slavoj Žižek: Why There Are No Viable Political Alternatives to Unbridled Capitalism | Big Think

Why There Are No Viable Political Alternatives to Unbridled Capitalism Watch the newest video from Big Think: https://bigth.ink/NewVideo Join Big Think Edge for exclusive videos: https://bigth.ink/Edge ---------------------------------------------------------------------------------- "B

From playlist Capitalism in the 21st century | Big Think

Video thumbnail

Definition of a Surjective Function and a Function that is NOT Surjective

We define what it means for a function to be surjective and explain the intuition behind the definition. We then do an example where we show a function is not surjective. Surjective functions are also called onto functions. Useful Math Supplies https://amzn.to/3Y5TGcv My Recording Gear ht

From playlist Injective, Surjective, and Bijective Functions

Video thumbnail

What It Takes to Lead a Nation

What leadership qualities should candidates--and presidents--demonstrate to successfully navigate the challenges they'll face? David Demarest, Stanford University's vice president for public affairs and former White House communications director, explains.

From playlist Wide Angle: Election 2016

Video thumbnail

The Curse of Oak Island: ORIGINS OF GOLD OBJECT REVEALED (Season 8) | History

Watch all new episodes of The Curse of Oak Island, Tuesdays at 9/8c, and stay up to date on all of your favorite History Channel shows at http://history.com/schedule. Rare coin expert, Sandy Campbell, reveals that the recently discovered gold-colored object was a knob possibly linked to a

From playlist The Curse of Oak Island: Season: 8 | New Episodes Tuesdays at 9/8c | History

Video thumbnail

These Bats Make Tiny Snow Caves

One might not think that snow could help anything stay warm through a harsh winter, but these tiny bats have found a way to utilize the insulation provided by the snow: they make little forts to wait out the winter. Hosted by: Michael Aranda SciShow has a spinoff podcast! It's called

From playlist The Weird World of Winter

Video thumbnail

The Korean War Iron Cross

Go to https://curiositystream.thld.co/markfelton_0722 and use code MARKFELTON to save 25% off today, that’s only $14.99 a year. Thanks to Curiosity Stream for sponsoring today’s video. Dr. Mark Felton FRHistS is a well-known British historian, the author of 22 non-fiction books, including

From playlist Korean Wars 1950-69

Video thumbnail

Nancy Adler, UC San Francisco - Stanford Medicine Big Data | Precision Health 2016

Bringing together thought leaders in large-scale data analysis and technology to transform the way we diagnose, treat and prevent disease. Visit our website at http://bigdata.stanford.edu/.

From playlist Big Data in Biomedicine: Enabling Precision Health Conference 2016

Video thumbnail

The Forgotten Hero of the Cape: Wolraad Woltemade

In 1773, the Dutch East India Company ship, Jonge Thomas, foundered off the cape of Good Hope. Only one man, sixty-five-year old Wolraad Woltemade, was willing to brave the storm and tide to rescue the survivors. His heroism deserves to be remembered. This is original content based on res

From playlist History without War

Video thumbnail

The "Racketeer Nickel"

Except for change, the nickel often escapes notice. But that wasn’t always true. In 1883, a nickel design was released that would cause enormous consternation for the U.S. mint, and led to fraud all over the country. The most famous fraudster of the 1883 ‘racketeer nickel,' is said to have

From playlist History without War

Video thumbnail

Nellie Tayloe Ross and the U.S. Mint

The Jefferson Nickel, the Roosevelt Dime and the Franklin Half Dollar were all created during a dynamic period of growth for the U.S. Mint under an extraordinary four-term director. The History guy recalls the life of Nellie Tayloe Ross, the first female governor of a U.S. state. All even

From playlist Wyoming

Video thumbnail

Aphorisms

An aphorism is a short sentence capturing a large truth in a pithy way. Here are some of the world’s finest. SUBSCRIBE to our channel for new films every week: http://tinyurl.com/o28mut7 If you like our films take a look at our shop (we ship worldwide): http://www.theschooloflife.com/shop/

From playlist SELF

Related pages

Term logic | Contraposition | Categorical proposition | Truth value | Inference | Square of opposition | Transposition (logic) | Logical equivalence | Proposition | Immediate inference