Inductive+&+Deductive

=Deductive & Inductive Reasoning =  In logic, there are two broad methods of reasoning, //**deductive**// and //**inductive.**//

**Click on the link below to see a version of the slide show on Inductive & Deductive Reasoning (from 2012)**
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Inductive Reasoning
Inductive reasoning moves from specific observations to broader generalizations. If you see one goose, you might think, geese are white, but you don't have a large enough sample to know. See two, and you begin to see a pattern, see the flock and you have a big enough sample to draw a conclusion: geese are white, or "most" geese are white.
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Sherlock Holmes, Silver Blaze
 In the short story, //The Adventure of Silver Blaze//, Sherlock Holmes solves a murder by establishing the __premise__ that dogs bark at strangers. Silver Blaze is a champion race horse who disappears from the stables the night his trainer is murdered. Holmes has two premises: 1) The dogs didn’t bark the night of the murderer broke into the barn where Silver Blaze was stabled, and 2) dogs bark at strangers. These premises lead Holmes to the __conclusion__ the dogs knew the murderer. His __ premise __ s turns out to be correct and lead to an accurate __ conclusion; Holmes solves the mystery and the murder __. One could argue he's used deductive reasoning, setting up the general premise, "dogs bark at strangers," and then the more specific, "these dogs did not bark at whoever entered the stables," therefore, "whoever entered the stables was not a stranger." One could also argue Holmes is using inductive reasoning, essentially reasoning by sign, (the clues), and perhaps by cause, (because dogs bark at strangers, therefore...) In fact, Holmes uses both forms of reasoning to solve crimes.

Here's a clip showing the dogs barking at Holmes. It's from an old (1988) BBC version of the story. Here's a link for more  Silver Blaze media type="youtube" key="NQbARjQRgzY" height="360" width="480"

Holmes' Hat Trick
Here's a clip from a Sherlock Holmes episode produced by the BBC in the 1980s. In it Holmes is establishing the character of a man he's never met simply by examining his hat and following the clues. Holmes basically uses Inductive reasoning to arrive at his conclusions. He establishes premises and then arrives at his conclusions based on them. media type="youtube" key="1bCS4icTrH0" height="360" width="480"

<span style="color: #000080; font-family: Georgia,serif;">Owls: Inductive Reasoning
<span style="color: #000080; font-family: Georgia,serif;">We can induce from these examples that owls (or most or many owls) have the ability to turn their heads in a unique way. We are reasoning from the one to the many. <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Example #1: Owl turning its head <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Example #2: Owl turning its head <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Example #3: Owl turning its head

<span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">[|Cheetah Girl—France 3 News] <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Cheetahs in Captivity <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Cheetah in Slow Motion <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">[|Cheetah Jumps on Car] <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Cheethas in the Serengeti, a documentary
 * <span style="color: #000080; font-family: 'Times New Roman'; font-size: 18.6667px; vertical-align: baseline;">Cheetah Videos **

<span style="color: #000080; font-family: Georgia,serif;">Deductive Reasoning:
<span style="color: #000080; font-family: Georgia,serif;">Men are many things beyond mortal. We don't know from the premise that all men are mortal, whether other creatures are mortal. We learn nothing about mortality from the first premise. We can not speculate about the mortality of Socrates because we don't know from the two premises whether he's a man. He could be the name of someone's dog. The second premise has to give us information about the category or quality we have explained.... in the above case that men are mortal.
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 * || <span style="color: #000080; font-family: Georgia,serif;">Men are many things beyond mortal. We don't know from the premise that all men are mortal, whether other creatures are mortal. We learn nothing about mortality from the first premise. We can not speculate about the mortality of Socrates because we don't know from the two premises whether he's a man. He could be the name of someone's dog. The second premise has to give us information about the category or quality we have explained.... in the above case that men are mortal. ||
 * <span style="color: #000080; font-family: Georgia,serif;">Properly formed deductive arguments are called **Valid Arguments** The conclusion of a valid deductive argument only makes explicit what is already contained in the premise s.<span style="color: #000080; font-family: Georgia,serif;"> In real life, of course, we can't always be sure of our premises, so the conclusions of real-life deductive arguments still have to be examined carefully. ||
 * [[image:Slide12.jpg width="415" height="320"]] || <span style="color: #000080; font-family: Georgia,serif;">For the logic to be formatted correctly, we would have to say that some old TV shows are penguins. The category being defined is penguins. Penguins are many things beyond "black and white." Look to the first term. ||

How Penguins gave up flying. [|How Einstein's Zebra Puzzle Works]