1.3 Deduction and Induction (cumulative)
inductive generalization
An inductive argument that proceeds from knowledge of a selected sample to some claim about the whole group Because the members of the sample have a certain characteristic or attribute, it is argued that all the members of the group have that same characteristic. For example, one might argue that Because three oranges selected from a certain crate were especially tasty and juicy, all the oranges from that crate are especially tasty and juicy. Or again, one might argue that Because six out of a total of nine members sampled from a certain labor union intend to vote for Johnson for union president, two-thirds of the entire membership intend to vote for Johnson. These examples of _________________ ____________________ illustrate the use of statistics in inductive argumentation
Inductive generalization
An inductive argument that proceeds from knowledge of a selected sample to some claim about the whole group.
argument based on signs
An inductive argument that proceeds from the knowledge of a sign to a claim about the thing or situation that the sign symbolizes Here is an example of an ___________________ _____________ _____ _____________: When driving on an unfamiliar highway one might see a sign indicating The road makes several sharp turns one mile ahead. Based on this information, one might argue that the road does indeed make several sharp turns one mile ahead. Because the sign might be misplaced or in error about the turns, the conclusion is only probable.
Argument based on signs
An inductive argument that proceeds from the knowledge of a sign to a claim about the thing or situation that the sign symbolizes.
causal inference
An inductive inference that proceeds from knowledge of a cause to a claim about an effect, or from knowledge of an effect to a claim about a cause Here are examples of ________________ _________________: From the knowledge that a bottle of wine had been accidentally left in the freezer overnight, someone might conclude The botlle of wine had frozen (cause to effect). Conversely, After tasting a piece of chicken and finding it dry and crunchy, one might conclude The chickend had been overcooked (effect to cause). Because specific instances of cause and effect can never be known with absolute certainty, one may usually interpret such arguments as inductive.
Causal inference
An inductive inference that proceeds from knowledge of a cause to a claim about an effect, or from knowledge of an effect to a claim about a cause.
Inductive (causal inference; also, the conclusion follows only probably from the premises and the special indicator word "may" suggests a probablisitic inference)
Animals that live on plant foods must eat large quantities of vegetation, and this consumes much of their time. Meat eaters, by contrast, have no need to eat so much or so often. Consequently, meat-eating hominines [/ˈhɒm əˌnaɪnz/ - early humans] may have had more leisure time available to explore and manipulate their environment; like lions and leopards, they would have time to spend lying around and playing. (William A. Haviland, Cultural Anthropology, 8th edition)
a deductive argument in which the conclusion depends on some purely arithmetic or geometric computation or measurement.
Argument based on mathematics
An inductive argument that proceeds from the knowledge of a sign to a claim about the thing or situation that the sign symbolizes.
Argument based on signs
An inductive argument that depends on the existence of a similarity between two things or states of affairs.
Argument from analogy
An inductive argument in which the conclusion rests on a statement made by some presumed authority or witness.
Argument from authority
A deductive argument in which the conclusion is claimed to depend merely on the definition of some word or phrase used in the premise or conclusion.
Argument from definition
Deductive (the conclusion follows necessarily from the premises; also, the special indicator words "it is certain" suggest a necessary inferfence)
Because the apparent daily movement which is common to both the planets and the fixed stars is seen to travel from the east to the west, but the far slower single movements of the single planets travel in the opposite direction from west to east, it is therefore certain that these movements cannot depend on the common movement of the world but should be assigned to the planets themselves. ( Johannes Kepler, Epitomy of Copernican Astronomy)
Deductive (the conclusion follows necessarily from the premises)
Because the moon moves relative to the earth so that it returns to the same position overhead after about 25 hours, there are two high and two low tides at any point every 25 hours. (Douglas C. Giancoli, The Ideas of Physics, 3rd edition)
Deductive (argument based on mathematics; also, the conclusion follows necessarily from the premises)
Because triangle A is congruent with triangle B, and triangle A is isosceles, it follows that triangle B is isosceles
a syllogism in which all three statements are categorical propositions.
Categorical syllogism
An inductive inference that proceeds from knowledge of a cause to a claim about an effect, or from knowledge of an effect to a claim about a cause.
Causal inference
Deductive (argument from definition; also, the conclusion follows necessarily from the premises)
Cholesterol is endogenous with humans. Therefore, it is manufactured inside the human body.
Inductive (causal inference; also, the conclusion follows only probably from the premises and the special indicator word "likely" suggests a probablistic inference)
Crater Lake, the deepest lake in the United States, was caused by a huge volcanic eruption 7700 years ago. Since human beings have lived around the mountain for more than 10,000 years, it is likely that people witnessed that eruption.
an argument in which the premises are claimed to support the conclusion in such a way that it is impossible for the premises to be true and the conclusion false.
Deductive argument
false
Deductive arguments always proceed from the general to the particular.
a syllogism having a disjunctive (either/or) statement for one or both of its premises.
Disjunctive syllogism
Deductive (the conclusion follows necessarily from the premises)
Each element, such as hydrogen and iron, has a set of gaps—wavelengths that it absorbs rather than radiates. So if those wavelengths are missing from the spectrum, you know that that element is present in the star you are observing. (Rick Gore, ''Eyes of Science'')
Deductive (disjunctive syllogism; also, the conclusion follows necessarily from the premises)
Either classical culture originated in Greece, or it originated in Egypt. Classical culture did not originate in Egypt. Therefore, classical culture originated in Greece.
Deductive (argument from definition; also, the conclusion follows necessarily from the premises)
Eternity is simultaneously whole. But time has a before and an after. Therefore time and eternity are not the same thing. (Thomas Aquinas, Summa Theologica)
Deductive (argument based on mathematics; also, the conclusion follows necessarily from the premises)
Even number yield even numbers when they are squared. It follows that the square roots of odd perfect squares are odd.
Inductive (prediction; also, the conclusion follows only probably from the conclusion)
Everyone who has ever tired to climb the Matterhorn has experienced terror at some stage of the ascent. Just you wait, John; sooner or later on your climb you are going to be afraid.
Deductive (the conclusion follows necessarily from the premises)
Everyone who is well educated knows about the existence of the Roman Empire, and John is well educated. So he has to know something about the Roman Empire.
A statement that makes a claim about all the members of a class.
General statement
Inductive (prediction; also, the conclusion follows only probably from the conclusion and the special indicator word "virtual certainty" suggest a probablistic inference)
Given present growth rates in underdeveloped countries, the limited practice of birth control, and the difficulty of slowing the current growth momentum, it can be said with virtual certainty that none of the people now reading this book will ever live in a world where the population is not growing. ( J. John Palen, Social Problems)
A syllogism having a conditional statement for one or both of its premises.
Hypothetical syllogism
Deductive (hypothetical syllogism; also, the conclusion follows necessarily from the premises)
If Alexander the Great died from typhoid fever, then he became infected in India. Alexander the Great did die from typhoid fever. Therefore, he became infected in India.
false
If an argument contains the phrase ''it definitely follows that,'' then we know for certain that the argument is deductive.
true
If the conclusion of an argument follows merely from the definition of a word used in a premise, the argument is deductive.
Inductive (argument from analogy; also, the conclusion follows only probably from the premises)
If you found a model of the solar system, you'd know that someone made it. How much more obvious is it, then, that the real solar system must have been made by somebody.
true
In a deductive argument, the conclusion is not supposed to contain more information than the premises.
true
In an inductive argument, it is intended that the conclusion contain more information than the premises.
an argument in which the premises are claimed to support the conclusion in such a way that it is improbable that the premises be true and the conclusion false.
Inductive argument
false
Inductive arguments always proceed from the particular to the general.
An inductive argument that proceeds from knowledge of a selected sample to some claim about the whole group.
Inductive generalization
Inductive (prediction; also, the conclusion follows only probably from the conclusion)
It seems likely that young people will be at war with old people in another 15 or 20 years. You can see it coming in the numbers. In 1900 only 1 percent of the population was older than 75. Today 4 percent of all Americans are more than 75 years old, and in a few years it's going to be 5 percent . . . 13 million people. (Newspaper editorial)
Deductive (argument from definition; also, the conclusion follows necessarily from the premises)
Lenses function by refracting light at their surfaces. Consequently, their action depends not only on the shape of the lens surfaces, but also on the indices of refraction of the lens material and the surrounding medium. (Frank J. Blatt, Principles of Physics, 2nd edition)
Inductive (causal inference; also, the conclusion follows only probably from the premises)
Look at these footprints in the mud by the window. We must have a peeping tom.
false
Most arguments based on statistical reasoning are deductive
Deductive (categorical syllogism; also, the conclusion follows necessarily from the premises)
No E-mail messages are eloquent creations. Some love letters are eloquent creations. Therefore, some love letters are not E-mail messages.
hominines
Noun /ˈhɒm əˌnaɪnz/ - early humans
Inductive (causal inference; also, the conclusion follows only probably from the premises)
When the Romans occupied England, coal was burned. Since coal produces quite a bit of soot and sulfur dioxide, there must have been days almost 2000 years ago when the air in the larger towns was badly polluted. (Stanley Gedzelman, The Science and Wonders of the Atmosphere)
Inductive (argument from authority; also, the conclusion follows only probably from the premises)
World-renowned physicist Stephen Hawking says that the condition of the universe at the instant of the Big Bang was more highly ordered than it is today. In view of Hawking's stature in the scientific community, we should conclude that this description of the universe is correct.
Inductive (argument from analogy; also, the conclusion follows only probably from the premises and the special indicator word "should" suggests a probablisitic inference)
[Psychologists] Wirtshafter and Davis noted that the glycerol content of the blood is related to the size of the fat cells [in the body]. Since the size of the fat cells would indicate something about the amount of stored fats, increases in blood glycerol should indicate increases in body weight. (Herbert L. Petri, Motivation: Theory and Research, 2nd edition)
General statement
A statement that makes a claim about all the members of a class.
Inductive (argument from analogy; also, the conclusion follows only probably from the premises)
Amoco, Exxon, and Texaco are all listed on the New York Stock Exchange. It must be the case that all major American oil companies are listed on the New York Stock Exchange.
false
An argument that draws a conclusion about a thing based on that thing's similarity to something else is a deductive argument.
false
An argument that draws a conclusion that something is true because someone has said that it is, is a deductive argument.
true
An argument that predicts what will happen in the future, based on what has happened in the past, is an inductive argument.
false
An argument that presents two alternatives and eliminates one, leaving the other as the conclusion, is an inductive argument.
true
An argument that proceeds from knowledge of a cause to knowledge of an effect is an inductive argument.
argument from authority
An inductive argument in which the conclusion rests on a statement made by some presumed authority or witness For example, a person might argue that Earnings for Hewlett-Packard Corporation will be up in the coming quarter because of a statement to that effect by an investment counselor. Or a lawyer might argue that Mack the Knife committed the murder because an eyewitness testified to that effect under oath. Because the investment counselor and the eyewitness could be either mistaken or lying, ___________ ________ _______________ are essentially probabilistic.
Argument from authority
An inductive argument in which the conclusion rests on a statement made by some presumed authority or witness.
argument from analogy
An inductive argument that depends on the existence of a similarity between two things or states of affairs Because of the existence of this analogy, a certain condition that affects the better-known thing or situation is concluded to affect the similar, lesser-known thing or situation. For example, someone might argue that Because Christina's Porsche is a great handling car, it follows that Angela's Porsche must also be a great handling car. The argument depends on the existence of a similarity, or analogy, between the two cars. The certitude attending to ________________ ________ _______________ is obviously probabilistic at best.
Argument from analogy
An inductive argument that depends on the existence of a similarity between two things or states of affairs.
summary
a brief statement that gives the most important information about something In ____________________, to distinguish deductive arguments from inductive, we 1. look for special indicator words 2. the actual strength of the inferential link between premises and conclusion 3. the character or form of argumentation. If the conclusion follows with strict necessity from the premises, the argument is always deductive; if not, it could be either deductive or inductive depending on the other factors. The deductive and inductive arguments that we have surveyed in this section are as follows: Deductive arguments: arguments based on mathematics arguments from definition categorical syllogisms hypothetical syllogisms disjunctive syllogisms Inductive arguments: predictions arguments from analogy inductive generalizations arguments from authority arguments based on signs causal inferences
Argument based on mathematics
a deductive argument in which the conclusion depends on some purely arithmetic or geometric computation or measurement.
inductive argument
an argument in which the premises are claimed to support the conclusion in such a way that it is improbable that the premises be true and the conclusion false In _________________ ________________ the conclusion is claimed to follow only probably from the premises. Example: The meerkat is closely related to the suricat. The suricat thrives on beetle larvae. Therefore, probably the meerkat thrives on beetle larvae. The conclusion follows only probably from the premises.
Inductive argument
an argument in which the premises are claimed to support the conclusion in such a way that it is improbable that the premises be true and the conclusion false.
prediction about the future
an inductive argument that proceeds from knowledge of some event in the relative past to a claim about some other event in the relative future For example, someone might argue that Because certain meteorological phenomena have been observed to develop over a certain region of central Missouri, a storm will occur there in six hours. Or again, one might argue that Because certain fluctuations occurred in the prime interest rate on Friday, the value of the dollar will decrease against foreign currencies on Monday. Nearly everyone realizes that the future cannot be known with certainty; thus, whenever an argument makes a ____________________ ____________ ____ _____________, one is usually justified in considering the argument inductive.
prediction
an inductive argument that proceeds from knowledge of some event in the relative past to a claim about some other event in the relative future.
actual strength of the inferential link
cohesiveness of an argument that suggests whether the argument should be taken as inductive or deductive The second factor that bears upon our interpretation of an argument as inductive or deductive is the ________ __________ __ ____ __________ ___________ between premises and conclusion. If the conclusion actually does follow with strict necessity from the premises, the argument is clearly deductive. In such an argument it is impossible for the premises to be true and the conclusion false. On the other hand, if the conclusion does not follow with strict necessity but does follow probably, it is usually best to consider the argument inductive. Examples: All saleswomen are extroverts. Elizabeth Taylor is a saleswoman. Therefore, Elizabeth Taylor is an extrovert. In this example, the conclusion follows with strict necessity from the premises. If we assume that all saleswomen are extroverts and that Elizabeth Taylor is a saleswoman, then it is impossible that Elizabeth Taylor not be an extrovert. Thus, we should interpret this argument as deductive. The vast majority of saleswomen are extroverts. Elizabeth Taylor is a saleswoman. Therefore, Elizabeth Taylor is an extrovert. In this example, the conclusion does not follow from the premises with strict necessity, but it does follow with some degree of probability. If we assume that the premises are true, then based on that assumption it is improbable that the conclusion is false. Thus, it is best to interpret this argument as inductive.
confuse
to mistakenly think that one person or thing is another person or thing : to mistake (one person or thing) for another Keeping this in mind, we should take care not to _________________ arguments in geometry, which are always deductive, with arguments from analogy or inductive generalizations. For example, An argument concluding that a triangle has a certain attribute (such as a right angle) because another triangle, with which it is congruent, also has that attribute might be mistaken for an argument from analogy. Similarly, an argument that concludes that all triangles have a certain attribute (such as angles totaling two right angles) because any particular triangle has that attribute might be mistaken for an inductive generalization. Arguments such as these, however, are always deductive, because the conclusion follows necessarily and with complete certainty from the premises.
Inductive (argument based on signs; also, the conclusion follows only probably from the premises)
We can go out the theater at the front; the exist sign points in that direction.
increment
(noun) a usually small amount or degree by which something is made larger or greater; addition They increased the dosage of the drug in small __________________ over a period of several weeks. Fines increase in ___________________ of $10. Antonym - reduction
argument based on mathematics
A deductive argument in which the conclusion depends on some purely arithmetic or geometric computation or measurement For example, A shopper might place two apples and three oranges into a paper bag and then conclude that the bag contains five pieces of fruit. Or A surveyor might measure a square piece of land and, after determining that it is 100 feet on each side, conclude that it contains 10,000 square feet. Since all arguments in pure mathematics are deductive, we can usually consider ______________ ___________ ____ _________________ to be deductive as well. A noteworthy exception, however, is arguments that depend on statistics. As we will see shortly, such arguments are usually best interpreted as inductive.
Argument from definition
A deductive argument in which the conclusion is claimed to depend merely on the definition of some word or phrase used in the premise or conclusion.
argument from definition
A deductive argument in which the conclusion is claimed to depend merely on the definition of some word or phrase used in the premise or conclusion. For example, Someone might argue that because Claudia is mendacious, it follows that she tells lies, or Because a certain paragraph is prolix, it follows that it is excessively wordy. These ______________ ________ _______________ are deductive because their conclusions follow with necessity from the definitions of ''mendacious'' and ''prolix.''
false
A geometrical proof is an example of an inductive argument.
general statement
A statement that makes a claim about one or more (but not all) members of a class A final point needs to be made about the distinction between inductive and deductive arguments. There is a tradition extending back to the time of Aristotle which holds that inductive arguments are those that proceed from the particular to the general, while deductive arguments are those that proceed from the general to the particular. (A _________________ _________________ is one that makes a claim about one or more particular members of a class, while a general statement makes a claim about all the members of a class.) It is true, of course, that many inductive and deductive arguments do work in this way; but this fact should not be used as a criterion for distinguishing induction from deduction. As a matter of fact, there are deductive arguments that proceed from the general to the general, from the particular to the particular, and from the particular to the general, as well as from the general to the particular; and there are inductive arguments that do the same. For example, here is a deductive argument that proceeds from the particular to the general: Three is a prime number. Five is a prime number. Seven is a prime number. Therefore, all odd numbers between two and eight are prime numbers. And here is one that proceeds from the particular to the particular: Gabriel is a wolf. Gabriel has a tail. Therefore, Gabriel's tail is the tail of a wolf. Here is an inductive argument that proceeds from the general to the particular: All emeralds previously found have been green. Therefore, the next emerald to be found will be green. The other varieties are easy to construct. Thus, the progression from particular to general, and vice versa, cannot be used as a criterion for distinguishing induction from deduction.
particular statement
A statement that makes a claim about one or more (but not all) members of a class A final point needs to be made about the distinction between inductive and deductive arguments. There is a tradition extending back to the time of Aristotle which holds that inductive arguments are those that proceed from the particular to the general, while deductive arguments are those that proceed from the general to the particular. (A _________________ _________________ is one that makes a claim about one or more particular members of a class, while a general statement makes a claim about all the members of a class.) It is true, of course, that many inductive and deductive arguments do work in this way; but this fact should not be used as a criterion for distinguishing induction from deduction. As a matter of fact, there are deductive arguments that proceed from the general to the general, from the particular to the particular, and from the particular to the general, as well as from the general to the particular; and there are inductive arguments that do the same. For example, here is a deductive argument that proceeds from the particular to the general: Three is a prime number. Five is a prime number. Seven is a prime number. Therefore, all odd numbers between two and eight are prime numbers. And here is one that proceeds from the particular to the particular: Gabriel is a wolf. Gabriel has a tail. Therefore, Gabriel's tail is the tail of a wolf. Here is an inductive argument that proceeds from the general to the particular: All emeralds previously found have been green. Therefore, the next emerald to be found will be green. The other varieties are easy to construct. Thus, the progression from particular to general, and vice versa, cannot be used as a criterion for distinguishing induction from deduction.
Particular statement
A statement that makes a claim about one or more (but not all) members of a class.
hypothetical syllogism
A syllogism having a conditional statement for one or both of its premises Examples: If electricity flows through a conductor, then a magnetic field is produced. If a magnetic field is produced, then a nearby compass will be deflected. Therefore, if electricity flows through a conductor, then a nearby compass will be deflected. If quartz scratches glass, then quartz is harder than glass. Quartz scratches glass. Therefore, quartz is harder than glass. Although certain forms of _________________ _________________ can sometimes be interpreted inductively, the deductive interpretation is usually the most appropriate
Hypothetical syllogism
A syllogism having a conditional statement for one or both of its premises.
Inductive (causal inference; also, the conclusion follows only probably from the premises)
Although both front and rear doors were found open after the burglary, there were pry marks around the lock on the rear door and deposits of mud near the threshold. It must be the case that the thief entered through the rear door and left through the front.
Inductive (prediction; also, the conclusion follows only probably from the premises)
Of course the sun will rise tomorrow--it's risen every day in human history.
Deductive (the conclusion follows necessarily from the premises)
Ordinary things that we encounter every day are electrically neutral. Therefore, since negatively charged electrons are a part of everything, positively charged particles must also exist in all matter. ( James E. Brady and Gerard E. Humiston, General Chemistry)
A statement that makes a claim about one or more (but not all) members of a class.
Particular statement
Inductive (prediction; also, the conclusion follows only probably from the conclusion and the special indicator word "could" suggests a probablistic inference)
Reserves of coal in the United States have an energy equivalent 33 times that of oil and natural gas. On a worldwide basis the multiple is about 10. By shifting to a coal-based economy, we could satisfy our energy requirements for at least a century, probably longer. (William L. Masterson and Emil J. Slowinski, Principles of Chemistry)
an argument consisting of exactly two premises and one conclusion.
Syllogism
Inductive (inductive generalization; also, the conclusion follows only probably from the conclusion)
Texans must all wear cowboy boots: I went to Houston last Thursday and everyone I saw on the street had them on.
Deductive (the conclusion follows necessarily from the premises)
That [the moons of Jupiter] revolve in unequal circles is manifestly deduced from the fact that at the longest elongation from Jupiter it is never possible to see two of these moons in conjunction, whereas in the vicinity of Jupiter they are found united two, three, and sometimes all four together. (Galileo Galilei, The Starry Messenger)
Inductive (argument from analogy; also, the conclusion follows only probably from the premises and the special indicator word "probably" suggests a probablistic inference)
The Encylopaedia Britannica has an article on symbiosis. The Encyclopedia Americana, like the Britannica, is an excellent reference work. Therefore, the Americana probably also has an article on symbiosis.
Deductive (the conclusion follows necessarily from the premises)
The Matterhorn is higher than Mount Whitney, and Mount Whitney is higher than Mount Rainier. The obvious conclusion is that the Matterhorn is higher than Mount Rainier.
Inductive (causal inference; also, the conclusion follows only probably from the premises)
The Simpson incident had shown me that a dog was kept in the stables, and yet, though someone had been in and had fetched out a horse, he had not barked enough to arouse the two lads in the loft. Obviously the midnight visitor was someone whom the dog knew well. (A. Conan Doyle, Memoirs of Sherlock Holmes)
true
The actual strength of the link between premises and conclusion may allow one to determine whether an argument is inductive or deductive.
true
The form of argumentation the arguer uses may allow one to determine whether an argument is inductive or deductive.
Deductive (the conclusion follows necessarily from the premises)
The graphical method for solving a system of equations is an approximation, since reading the point of intersection depends on the accuracy with which the lines are drawn and on the ability to interpret the coordinates of the point. (Karl J. Smith and Patrick J. Boyle, Intermediate Algebra for College Students)
Deductive (the conclusion follows necessarily from the premises)
The interpretation of the laws is the proper and peculiar province of the courts. A constitution is, in fact, and must be regarded by the judges, as a fundamental law. It therefore belongs to them to ascertain its meaning, as well as the meaning of any particular act proceeding from the legislativebody. (Alexander Hamilton, Federalist Papers, No. 78)
Inductive (argument based on signs; also, the conclusion follows only probably from the premises)
The plaque on the leaning tower of Pisa says that Galileo performed experiments there with falling objects. It must be the case that Galileo did indeed perform those experiments there.
Inductive (prediction; also, the conclusion follows only probably from the conclusion and the special indicator word "probably" suggests a probablistic inference)
The rainfall in Seattle has been more than 15 inches every year for the past thirty years. Therefore, the rainfall next year will probably be more than 15 inches.
Deductive (argument based on mathematics; also, the conclusion follows necessarily from the premises)
This circle has an area of exactly 4 inches. So a circle with an area of 1 square inch would have a radius half as long.
Inductive (argument from analogy; also, the conclusion follows only probably from the premises)
This fish looks very similar to a trout or salmon. Since those fish are tasty, this one must be tasty, too.
argument
a group of statements, one or more of which (the premises) are claimed to provide support for, or reasons to believe, one of the others (the conclusion). ______________________ can be divided into two groups: deductive and inductive. A deductive argument is an argument in which the premises are claimed to support the conclusion in such a way that it is impossible for the premises to be true and the conclusion false. In such arguments the conclusion is claimed to follow necessarily from the premises. Example, The meerkat is a member of the mongoose family. All members of the mongoose family are carnivores. Therefore, it necessarily follows that the meerkat is a carnivore. On the other hand, an inductive argument is an argument in which the premises are claimed to support the conclusion in such a way that it is improbable that the premises be true and the conclusion false. In these arguments the conclusion is claimed to follow only probably from the premises. Example, The meerkat is closely related to the suricat. The suricat thrives on beetle larvae. Therefore, probably the meerkat thrives on beetle larvae. Thus, deductive arguments are those that involve necessary reasoning, and inductive arguments are those that involve probabilistic reasoning.
meteorology
a science that deals with the atmosphere, especially with weather The study of ____________________ dates back millennia, though significant progress in meteorology did not occur until the 18th century.
scientific argument
a science-‐based claim that is supported by evidence _________________ ______________ can be either inductive or deductive, depending on the circumstances. In general, arguments aimed at the discovery of a law of nature are usually considered inductive. Suppose, for example, that we want to discover a law that governs the time required for a falling body to strike the earth. We drop bodies of various weights from various heights and measure the time it takes them to fall. Comparing our measurements, we notice that the time is approximately proportional to the square root of the distance. From this we conclude that the time required for any body to fall is proportional to the square root of the distance through which it falls. Such an argument is best interpreted as an inductive generalization. Another type of argument that occurs in science has to do with the application of known laws to specific circumstances. Arguments of this sort are often considered to be deductive—but only with certain reservations. Suppose, for example, that we want to apply Boyle's law for ideal gases to a container of gas in our laboratory. Boyle's law states that the pressure exerted by a gas on the walls of its container is inversely proportional to the volume. Applying this law, we conclude that when we reduce the volume of our laboratory sample by half, we will double the pressure. Considered purely as a mathematical computation, this argument is deductive. But if we acknowledge the fact that the conclusion pertains to the future and the possibility that Boyle's law may not work in the future, then the argument is best considered inductive.
distinction between inductive and deductive arguments
a set of factors for distinguishing inductive from deductive arguments The _____________ __________ ___________ ______ ____________ ______________ lies in the strength of an argument's inferential claim. In other words, the distinction lies in how strongly the conclusion is claimed to follow from the premises. Unfortunately, however, in most arguments the strength of this claim is not explicitly stated, so we must use our interpretive abilities to evaluate it. Three factors that influence our decision about this claim are (1) the occurrence of special indicator words. (2) the actual strength of the inferential link between premises and conclusion. (3) the character or form of argumentation the arguer uses.
Disjunctive syllogism
a syllogism having a disjunctive (either/or) statement for one or both of its premises.
disjunctive syllogism
a syllogism having a disjunctive statement (i.e., an ''either . . . or . . .'' statement) for one or both of its premises Example: Either breach of contract is a crime or it is not punishable by the state. Breach of contract is not a crime. Therefore, it is not punishable by the state. As with hypothetical syllogisms, _______________ ________________ are usually best taken as deductive.
Categorical syllogism
a syllogism in which all three statements are categorical propositions.
categorical syllogism
a syllogism in which all three statements are categorical propositions. In other words, a _________________ _________________ is a syllogism in which each statement begins with one of the words ''all,'' ''no,'' or ''some.'' Example: All lasers are optical devices. Some lasers are surgical instruments. Therefore, some optical devices are surgical instruments. Arguments such as these are nearly always best treated as deductive.
meteorological
adjective (mē′tē-ər-ə-lŏj′ĭ-kəl)
Syllogism
an argument consisting of exactly two premises and one conclusion.
syllogism
an argument consisting of exactly two premises and one conclusion. The following is a categorical __________________. All adlers are bobkins. All bobkins are crockers. Therefore, all adlers are crockers.
Deductive argument
an argument in which the premises are claimed to support the conclusion in such a way that it is impossible for the premises to be true and the conclusion false.
deductive argument
an argument in which the premises are claimed to support the conclusion in such a way that it is impossible for the premises to be true and the conclusion false. In _______________ ________________ the conclusion is claimed to follow necessarily from the premises. Example: The meerkat is a member of the mongoose family. All members of the mongoose family are carnivores. Therefore, it necessarily follows that the meerkat is a carnivore. The conclusion follows necessarily from the premises.
special indicator words
expressions of an argument that suggest whether the argument should be interpreted as inductive or deductive The occurrence of ___________ __________ ___________ is illustrated in these examples. The meerkat is closely related to the suricat. The suricat thrives on beetle larvae. Therefore, probably the meerkat thrives on beetle larvae. The meerkat is a member of the mongoose family. All members of the mongoose family are carnivores. Therefore, it necessarily follows that the meerkat is a carnivore. The word ''probably'' in the conclusion of the first argument suggests that the argument should be taken as inductive, and the word ''necessarily'' in the conclusion of the second suggests that the second argument be taken as deductive. Additional inductive indicators are ''improbable,'' ''plausible,'' ''implausible,'' ''likely,'' ''unlikely,'' and ''reasonable to conclude.'' Additional deductive indicators are ''certainly,'' ''absolutely,'' and ''definitely.'' (Note that the phrase ''it must be the case that'' is ambiguous; ''must'' can indicate either probability or necessity). Inductive and deductive indicator words often suggest the correct interpretation. However, if they conflict with one of the other criteria (discussed shortly), we should probably ignore them. Arguers often use phrases such as ''it certainly follows that'' for rhetorical purposes to add impact to their conclusion and not to suggest that the argument be taken as deductive. Similarly, some arguers, not knowing the distinction between inductive and deductive, will claim to ''deduce'' a conclusion when their argument is more correctly interpreted as inductive.
mutually exclusive
not able to be true or exist at the same time; contradictory It should be noted that the various subspecies of inductive arguments listed here are not intended to be _________________ _________________. Overlaps can and do occur. For example, many causal inferences that proceed from cause to effect also qualify as predictions. The purpose of this survey is not to demarcate in precise terms the various forms of induction but rather to provide guidelines for distinguishing induction from deduction.
meteorology
noun (mē′tē-ə-rŏl′ə-jē)
increment
noun (ĭn′krə-mənt)
meteorological
noun of or pertaining to atmospheric phenomena, especially weather and weather conditions; weather, climate The weatherperson forcasted adverse ____________________ conditions.
an inductive argument that proceeds from knowledge of some event in the relative past to a claim about some other event in the relative future.
prediction
character or form of argumentation
structure of an argument that suggests whether the argument should be taken as inductive or deductive Occasionally, an argument contains no indicator words, and the conclusion does not follow either necessarily or probably from the premises; in other words, it does not follow at all. This situation points up the need for the third factor to be taken into account, which is the _____________ ____ _________ ___ ____________________ the arguer uses. Five examples of argumentation that are typically deductive are 1. arguments based on mathematics 2. arguments from definition 3. categorical syllogiisms 4. hypothetical syllogisms 5. disjunctive syllogisms. Additional ones will be addressed in later chapters. Now let us consider some typically inductive forms of argumentation. In general, inductive arguments are such that the content of the conclusion is in some way intended to ''go beyond'' the content of the premises. The premises of such an argument typically deal with some subject that is relatively familiar, and the conclusion then moves beyond this to a subject that is less familiar or that little is known about. Such an argument may take any of several (many) forms: 1. predictions about the future 2. arguments from analogy 3. inductive generalizations 4.. arguments from authority 5. arguments based on signs 6. causal inferences, to name just a few
precede
to go before; to preface Riots _______________ the civil war. She _________________ him into the room. NTBCW (verb) "proceed" - progress, emanate, ensue; move or go forward; to carry on: Please ______________ to the exit.
precede
verb (prĭ-sēd′)
proceed
verb (prə-sēd′)
proceed
verb progress, emanate, ensue; move or go forward; to carry on: Please __________________ to the exit. NTBCW: (verb) "precede" - to go before; to preface; She ___________ him into the room.
