Logic Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! ===Aristotelian=== {{main|Aristotelian logic}} [[Aristotelian logic]] encompasses a great variety of topics. They include [[Metaphysics|metaphysical]] theses about [[Ontology|ontological]] categories and problems of scientific explanation. But in a more narrow sense, it is identical to [[term logic]] or syllogistics. A [[syllogism]] is a form of argument involving three propositions: two premises and a conclusion. Each proposition has three essential parts: a [[Subject (grammar)|subject]], a predicate, and a [[Copula (linguistics)|copula]] connecting the subject to the predicate.{{sfnm|1a1=Smith|1y=2022|2a1=Groarke|3a1=Bobzien|3y=2020}} For example, the proposition "Socrates is wise" is made up of the subject "Socrates", the predicate "wise", and the copula "is".{{sfn |Groarke}} The subject and the predicate are the ''terms'' of the proposition. Aristotelian logic does not contain complex propositions made up of simple propositions. It differs in this aspect from propositional logic, in which any two propositions can be linked using a logical connective like "and" to form a new complex proposition.{{sfnm|1a1=Smith|1y=2022|2a1=Magnus|2y=2005|2loc=2.2 Connectives}} [[File:Square of opposition, set diagrams.svg|thumb|upright=1.4|alt=Diagram of the square of opposition|The [[square of opposition]] is often used to visualize the relations between the four basic [[categorical propositions]] in Aristotelian logic. It shows, for example, that the propositions "All S are P" and "Some S are not P" are contradictory, meaning that one of them has to be true while the other is false.]] In Aristotelian logic, the subject can be ''universal'', ''particular'', ''indefinite'', or ''singular''. For example, the term "all humans" is a universal subject in the proposition "all humans are mortal". A similar proposition could be formed by replacing it with the particular term "some humans", the indefinite term "a human", or the singular term "Socrates".{{sfnm|1a1=Smith|1y=2022|2a1=Bobzien|2y=2020|3a1=Hintikka|3a2=Spade|3loc=[https://www.britannica.com/topic/history-of-logic/Aristotle Aristotle]}} Aristotelian logic only includes predicates for simple [[Property (philosophy)|properties]] of entities. But it lacks predicates corresponding to [[Relations (philosophy)|relations]] between entities.{{sfn |Westerståhl |1989 |pp=577–585}} The predicate can be linked to the subject in two ways: either by affirming it or by denying it.{{sfnm|1a1=Smith|1y=2022|2a1=Groarke}} For example, the proposition "Socrates is not a cat" involves the denial of the predicate "cat" to the subject "Socrates". Using combinations of subjects and predicates, a great variety of propositions and syllogisms can be formed. Syllogisms are characterized by the fact that the premises are linked to each other and to the conclusion by sharing one predicate in each case.{{sfnm|1a1=Smith|1y=2022|2a1=Hurley|2y=2015|2loc=4. Categorical Syllogisms|3a1=Copi|3a2=Cohen|3a3=Rodych|3y=2019|3loc=[https://books.google.com/books?id=38bADwAAQBAJ&pg=PA187 6. Categorical Syllogisms]}} Thus, these three propositions contain three predicates, referred to as ''major term'', ''minor term'', and ''middle term''.{{sfnm|1a1=Groarke|2a1=Hurley|2y=2015|2loc=4. Categorical Syllogisms|3a1=Copi|3a2=Cohen|3a3=Rodych|3y=2019|3loc=[https://books.google.com/books?id=38bADwAAQBAJ&pg=PA187 6. Categorical Syllogisms]}} The central aspect of Aristotelian logic involves classifying all possible syllogisms into valid and invalid arguments according to how the propositions are formed.{{sfnm|1a1=Smith|1y=2022|2a1=Groarke}}{{sfn |Hurley |2015 |loc=4. Categorical Syllogisms}} For example, the syllogism "all men are mortal; Socrates is a man; therefore Socrates is mortal" is valid. The syllogism "all cats are mortal; Socrates is mortal; therefore Socrates is a cat", on the other hand, is invalid.{{sfn |Spriggs |2012 |pp=20–2}} Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page