Logic 101: Introducing Basic Inductive and Deductive Arguments

I Introduce the basics on what constitutes "inductive arguments" and deductive arguments" as part 1 of my introduction to logic and argumentation series.


Key Points:

*A deductive argument is intended to provide absolute and conclusive support for its conclusion.

*A deductive argument that succeeds in providing conclusive support for its conclusion is said to be valid. A valid argument is such that if all its premises are true, the conclusion must be true.

*A deductively valid argument with true premises is said to be sound.

*An inductive argument that succeeds in providing probable support for its conclusion is said to be strong. A strong argument is such that if its premises are true, its conclusion is probably true.

*An inductively strong argument with true premises is said to be cogent.

Category:

Education

Tags:

• Logic
• Introduction
• 101
• Philosophy
• Explained
• Argumentation
• Theory
• Argument
• Deduction
• Deductive
• Induction
• Inductive
• Reason
• Critical
• Thinking
• Reasoning
• Laws
• of
• Thought
• Truth
• Falsity
• Epistemology
• Rational
• Logos
• fallacies
• Validity
• Sound
• Cogent
• Consistency
• Organon
• Binary

[tgoolsby2]

Look at what is said at 3:00

Now if I say:

All humans are mammals.

Bob is a mammals.

Therefore Bob is a human.

The premises are true but the conclusion may or may not be true. Unless at 3:00 I was supposed to assume the argument was valid at that point.

[AnarchistPhilosopher]

@tgoolsby2

To have a valid logical argument the conclusion must logically follow from the premises i.e. the structure of the argument must be such that if the premises are true the conclusion MUST also be true. In the instance you just have given, the conclusion doesn't "necessarily" follow from the premises, as something could be a mammal but not be a human.

[ToadHead]

Only individual statements (or propositions, if you insist) may be true or false. Statements are true if the state of affairs in the real world correlates with the concept expressed in the statement.

The term "true" should never be applied to arguments. Arguments are groups of statements, not single statements.

"It's just as easy to get these things right as it is to get them wrong." -- Graham Chapman (1941 - 1989)

[AnarchistPhilosopher]

@ToadHead

If individual statements can be true or false then ordered sets of individual statements (arguments) can also be true or false

It doesn't make sense to say you can only have individual segments without a set, or concrete particulars without a universal. It's like saying: you can have trees but not a forest, or water molecules but not an ocean

[TheRationalizer]

So a valid deductive argument that is true can prove something to be false? :)

I presume the idea that humans and apes share a common ancestor is a highly probable inductive argument?

[AnarchistPhilosopher]

@TheRationalizer

Yes you could use a valid deductive argument to disprove something.

EX:

1) All circular arguments are necessarily false

2) The divine right of kings is a circular argument

3) Therefore it follows that the divine right of kings is necessarily false

And yes, the idea that apes share a common ancestor with modern humans (which follows from what we know about evolution by natural selection) is a highly probable inductive argument.

[Stigandr005]

@tjr3838 Your comment is incoherent and practically irrelevant to what the video is about. This video deals with logical form and constructing truth preserving arguments; all you are doing is making assertions about people lying, inferring a bunch of nonsense based on what he doesn't say, and then vaguely criticizing him for it...that's just great.

[immortaldyna]

9:47 you said highly likely or high unlikely?

[JanelleSant]

Well done! I learned a lot in a little time. It was both clear and interesting! How it should be done!

[lalala22333]

kill me, i had to hear this for my homework

[RavenDemos]

I have just realized something laughable as I was scanning the replies- the complete difference of length and content of the replies when comparing the replies of a video such as this one to a video such as a music video. It was refreshing when I was reading comments and didn't even see a single "f" word! Thank you for the beginning video of the topic, it was nice to watch before going into my logic text book.

[RavenDemos]

Forgive me for not writing an essay of a reply, but I just realized something- The extreme difference in length and content of the replies of videos like this one, and videos like music vidoes.

[1305ali]

hey for the inductive argument you forgot to mention that inductively strong arguments are "cogent" just like deductively valid arguments are "Strong". its a superb video it will help alot of people. thanks.

[etramway]

We should be teaching this as a component of all education curriculum. Just teaching students which buttons to push is a failing in higher education that is destroying our democracy.

[crescentmoon610]

@AnarchistPhilosopher So therefore, his argument would be an invalid deductive argument? Thanks for the great video by they way.