What is the obverse in logic?

Published by Charlie Davidson on

What is the obverse in logic?

a form of inference in which a negative proposition is obtained from an affirmative, or vice versa, as “None of us is immortal” is obtained by obversion from “All of us are mortal.”

What is an example of obverse?

Thus, for example, the obverse of “All ants are insects” is “No ants are non-insects”; the obverse of “No fish are mammals” is “All fish are non-mammals”; the obverse of “Some musicians are males” is “Some musicians are not non-males”; and the obverse of “Some cars are not sedans” is “Some cars are non-sedans.”

What does obverse mean?

1 : facing the observer or opponent. 2 : having the base narrower than the top an obverse leaf. 3 : constituting the obverse of something : opposite.

What is an obverse claim?

Obverse. The obverse of a categorical claim is that claim that is directly across from it in the square of opposition, with the predicate term changed to its complementary term.

What are the 4 types of categorical proposition?

There are four types of categorical proposition, each of which is given a vowel letter A, E, I and O. A way of remembering these is: Affirmative universal, nEgative universal, affIrmative particular and nOgative particular.

What is immediate inference give example?

An immediate inference is an inference which can be made from only one statement or proposition. For instance, from the statement “All toads are green”, the immediate inference can be made that “no toads are not green” or “no toads are non-green” (Obverse).

How do you use obverse?

Obverse in a Sentence 🔉

  1. While I thought my parents would be happy I got a job, the obverse was true when they learned I’d be working in a strip club.
  2. Sadness is the obverse or opposite of happiness.
  3. As a child, I quickly learned “no” was the disappointing obverse of “yes.”

What is the difference between obverse and converse?

The valid converse is logically equivalent to the original proposition. The obverse is logically equivalent to the original proposition.

What means antipode?

Definition of antipode 1 : the parts of the earth diametrically opposite —usually used in plural —often used of Australia and New Zealand as contrasted to the western hemisphere. 2 : the exact opposite or contrary.

What is a categorical sentence?

In this chapter we will be looking at a special kind of statement called categorical. They are so called because sentences that express them can be interpreted as asserting a relation between two categories or classes of things. Some examples of sentences expressing categorical statements are: All mice are rodents.

How do you identify categorical propositions?

Thus, categorical propositions are of four basic forms: “Every S is P,” “No S is P,” “Some S is P,” and “Some S is not P.” These forms are designated by the letters A, E, I, and O, respectively, so that “Every man is mortal,” for example, is an A-proposition.

Which is the best definition of obverse logic?

1. an act or instance of obverting. 2. a form of inference in which a negative proposition is obtained from an affirmative, or vice versa, as “None of us is immortal” is obtained by obversion from “All of us are mortal.”. [1840–50; < Late Latin]

What is the definition of obversion in logic?

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…

Is the obverse the same as the original proposition?

Obversion is the inference in which the quality of the proposition is changed and the predicate is interchanged with its complement. It is valid for all four forms. The obverse is logically equivalent to the original proposition.

Which is the best definition of the word obverse?

[noun ob-vurs; adjective ob-vurs, ob-vurs] See more synonyms for obverse on Thesaurus.com. noun. the side of a coin, medal, flag, etc., that bears the principal design (opposed to reverse). the front or principal surface of anything. a counterpart.

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