Posted on 07/27/2017 6:06:58 PM PDT by ETL
During the scientific process, deductive reasoning is used to reach a logical true conclusion. Another type of reasoning, inductive, is also used. Often, people confuse deductive reasoning with inductive reasoning, and vice versa. It is important to learn the meaning of each type of reasoning so that proper logic can be identified.
Deductive reasoning
Deductive reasoning is a basic form of valid reasoning. Deductive reasoning, or deduction, starts out with a general statement, or hypothesis, and examines the possibilities to reach a specific, logical conclusion, according to the University of California.
The scientific method uses deduction to test hypotheses and theories. "In deductive inference, we hold a theory and based on it we make a prediction of its consequences. That is, we predict what the observations should be if the theory were correct. We go from the general — the theory — to the specific — the observations," said Dr. Sylvia Wassertheil-Smoller, a researcher and professor emerita at Albert Einstein College of Medicine.
Deductive reasoning usually follows steps. First, there is a premise, then a second premise, and finally an inference. A common form of deductive reasoning is the syllogism, in which two statements — a major premise and a minor premise — reach a logical conclusion. For example, the premise "Every A is B" could be followed by another premise, "This C is A."
Those statements would lead to the conclusion "This C is B." Syllogisms are considered a good way to test deductive reasoning to make sure the argument is valid.
For example, "All men are mortal. Harold is a man. Therefore, Harold is mortal." For deductive reasoning to be sound, the hypothesis must be correct. It is assumed that the premises, "All men are mortal" and "Harold is a man" are true. Therefore, the conclusion is logical and true.
In deductive reasoning, if something is true of a class of things in general, it is also true for all members of that class.
According to the University of California, deductive inference conclusions are certain provided the premises are true. It's possible to come to a logical conclusion even if the generalization is not true. If the generalization is wrong, the conclusion may be logical, but it may also be untrue.
For example, the argument, "All bald men are grandfathers. Harold is bald. Therefore, Harold is a grandfather," is valid logically but it is untrue because the original statement is false.
Inductive reasoning
Inductive reasoning is the opposite of deductive reasoning. Inductive reasoning makes broad generalizations from specific observations.
Basically, there is data, then conclusions are drawn from the data. This is called inductive logic, according to Utah State University.
"In inductive inference, we go from the specific to the general. We make many observations, discern a pattern, make a generalization, and infer an explanation or a theory," Wassertheil-Smoller told Live Science.
"In science, there is a constant interplay between inductive inference (based on observations) and deductive inference (based on theory), until we get closer and closer to the 'truth,' which we can only approach but not ascertain with complete certainty."
An example of inductive logic is, "The coin I pulled from the bag is a penny. That coin is a penny. A third coin from the bag is a penny. Therefore, all the coins in the bag are pennies."
Even if all of the premises are true in a statement, inductive reasoning allows for the conclusion to be false. Here's an example: "Harold is a grandfather. Harold is bald. Therefore, all grandfathers are bald." The conclusion does not follow logically from the statements.
Inductive reasoning has its place in the scientific method. Scientists use it to form hypotheses and theories. Deductive reasoning allows them to apply the theories to specific situations.
Abductive reasoning
Another form of scientific reasoning that doesn't fit in with inductive or deductive reasoning is abductive. Abductive reasoning usually starts with an incomplete set of observations and proceeds to the likeliest possible explanation for the group of observations, according to Butte College.
It is based on making and testing hypotheses using the best information available. It often entails making an educated guess after observing a phenomenon for which there is no clear explanation.
For example, a person walks into their living room and finds torn up papers all over the floor. The person's dog has been alone in the room all day. The person concludes that the dog tore up the papers because it is the most likely scenario. Now, the person's sister may have brought by his niece and she may have torn up the papers, or it may have been done by the landlord, but the dog theory is the more likely conclusion.
Abductive reasoning is useful for forming hypotheses to be tested. Abductive reasoning is often used by doctors who make a diagnosis based on test results and by jurors who make decisions based on the evidence presented to them.
The roots of our tree of knowledge are inductive reasoning, the branches are deductive.
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“For example, “All men are mortal. Harold is a man. Therefore, Harold is mortal.” For deductive reasoning to be sound, the hypothesis must be correct. It is assumed that the premises, “All men are mortal” and “Harold is a man” are true. Therefore, the conclusion is logical and true.”
Suppose “Harold” is a transgender?
Ping for later
#TechnicalCorrectnessMatters
Racist.
Inductive reasoning is data driven, and is often the focus of machine learning. You are looking for patterns in data that can be translated into effective rules. Deductive is looking at facts/evidence (which probably don’t have a pattern) and drawing conclusions. Of the two, deductive requires more imagination (IMHO).
Lol! What was your line of reasoning in order to reach that conclusion?
"In science, there is a constant interplay between inductive inference (based on observations) and deductive inference (based on theory), until we get closer and closer to the 'truth,' which we can only approach but not ascertain with complete certainty."
The exception, as you pointed out, is global warming where the science is "settled" and the premise is beyond contestation in spite of the fact that in forty years it has failed to accurately predict a single event or condition even ONCE!!!
1. No mayten tree is deciduous, and all nondeciduous trees are evergreens. It follows that all mayten trees are evergreens.
A) Inductive
B) Deductive
2. Mike must belong to the Bartenders and Beverage Union Local 165, since almost every Los Vegas bartender does.
A) Inductive
B) Deductive
3. Either Colonel Mustard or Reverend Green killed Professor Plum. But whoever ran off with Mrs. White did not kill the professor. Since Reverend Green ran off with Mrs. White, Colonel Mustard killed Professor Plum.
A) Inductive
B) Deductive
4. I’ve never met a golden retriever with a nasty disposition. I bet there aren’t any.
A) Deductive
B) Inductive
5. Since some grapes are purple, and all grapes are fruit, some fruit is purple.
A) Deductive
B) Inductive
6. Why is Sarah so mean to Janice? The only thing I can think of is that she’s jealous. Jealousy is what’s making her mean.
A) Deductive
B) Inductive
7. Obama will make a fine president. After all, he made a fine senator.
A) Inductive
B) Deductive
8. The figure he drew has only three sides, so it isn’t a square.
A) Deductive
B) Inductive
9. It was the pizza that made my stomach churn. What else could it be? I was fine until I ate it.
A) Deductive
B) Inductive
10. It’s wrong to hurt someone’s feelings, and that is exactly what you are doing when you speak to me like that.
A) Deductive
B) Inductive
If you’re stumped on any of these, answers are provided here:
https://www.thatquiz.org/tq/previewtest?F/Z/J/V/O3UL1355243858
Boy sees girl.
Boy uses Inductive Method. [This girl is beautiful]
Girl sees boy seeing her.
Girl uses Deductive Method. [All men are slobs.]
Boy uses Seductive method.
Boy and Girl lose Critique of Pure Reason.
Lol! Sorry, folks! Didn’t notice this one before posting the quiz. In any case, a third choice is obviously needed here.
7. Obama will make a fine president. After all, he made a fine senator.
A) Inductive
B) Deductive
This is only conjecture on my part; since I'm not a white male I'm kind of shaky on linear reasoning. :-)
For example, if you can prove that something is true for 1, and is also true for n + 1, then you can show it is true for all positive integers. Even though this is incorrectly called an 'inductive proof', it is really pure deduction.
Induction also goes by the name of empirical. Because induction depends on what is observed it can never prove anything conclusively. No matter how many white swans you see, you can never be certain that there isn't a black swan hanging out in some pond you've never had a chance to visit.
That's why Newton could later be refuted by Einstein even though Newton's Laws are a pretty darn good approximation for everything much larger than atoms, and all of the evidence prior to the 20th century validated Newton's claims.
Also why Aristotle's Law that F = mv was a pretty good approximation at a time when most common surfaces had lots of friction.
>>Of course very little of this applies to the bogus ‘science’ of man-made global warming. There the rules of scientific reasoning fly out the window. <<
AGW is an example of Investment Reasoning.
The definition of Investment Reasoning is: If enough money is invested in a certain outcome of a series of theories, scientists will do all they can to arrive at that outcome.
This also known as the “draw your lines then plot your points” approach.
Deductive reasoning test with figures
Test your IQ with this deductive reasoning test using Latin squares. Use your logical reasoning skills to fill the missing cells of the Latin square.
https://www.123test.com/deductive-reasoning-test-figures/
So what sort of reasoning is “I get grant money for researching global warming, therefore global warming is real”.
“draw your lines then [fudge] your points” approach. :)
Standard Libtard-type reasoning?
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