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FALLACIES IN LOGIC. 6th Meeting. Sense of Fallacy. Fallacy is a type of argument that may seem to be correct, but that proves on examination not to be so. Kinds of informal fallacy. Meaning of the fallacy of relevance.
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FALLACIES IN LOGIC 6th Meeting
Sense of Fallacy Fallacy is a type of argument that may seem to be correct, but that proves on examination not to be so.
Meaning of the fallacy of relevance The mistaken arguments rely on premises that may seem to be relevant to the conclusion but in fact are not.
. Kinds of Relevance Fallacy
Argument from ignorance (ad ignorantiam) When it is argued that a proposition is true on the ground that it has not been prove false, or when it is argued that a proposition is false because it has not been proved true. Example: This is used in a criminal court, where a suspect is presumed innocent until proved guilty
Appeal to inappropriate authority (ad verecundiam) When the premises of an argument appeal to some party or parties having no legitimate claim to authority in the matter at hand. Example: But can you doubt that air has weight when you have the clear testimony of Aristotle affirming that all the elements have weight including air, and excepting only fire?
Complex question When a question is asked in such a way as to presuppose the truth of some assumption buried in that question. Example: Lawyer: the figure seem to indicate that your sales increased as a result of these misleading advertisements. Is that correct? Witness: they did not. Lawyer: But you do admit, then, that your advertising was misleading. How long have you been engaging in practices like these?
Argument against the person (ad hominem) When an attack is leveled not at the calims or conclusions of an opponent, but at person of the opponent. Two forms of it: 1. Abusive ad hominem: When the attack is directly against a persons, seeking to defame or discredit them, it is called an “abusive ad hominem.” 2. Circumstantial ad hominem: When the attack is indirectly against persons, suggesting that they adopt their views chiefly because of their special circumstances or interests, it is called a “circumstantial ad hominem.”
Example: For, if the distinction of degrees is infinite, so that there is among them no degree, thatn which no higher can be found, our course of reasoning reaches this conclusion: that the multitude of natures themselves is not limited by any bounds. But only an absurdly foolish man can fail to regard such a conclusion as absurdly foolish. There is, then, necessarily some nature which is so superior to some natures, that there is none in comparison with which it is ranked as inferior.
Accident When one applies a generalization to an individual case that it does not properly Govern. Example: It has been a common that candidate invites politician to hear the competency of the candidate. I also socialized my competency as the candidate of the Bank of Indoesia. So I did not do any mistake
Converse accident When one moves carelessly or too quickly from a single case to an indefensibly broad Generalization Example: Take my son, Martyn. He’s been eating fish and chips his whole life, and he just had a cholesterol test, and his level is below the national average. What better proff could there be than a frier’s son?
False cause When one treats as the cause of a thing what is not really the cause of that thing; or more generally, when one blunders badly in reasoning based on causal relations. Example: beating drums or kentongan is the cause of the sun’s reappearance after solar eclipse.
Appeal to pity (ad misericordiam) When careful reasoning is replaced by devices calculated to cause sympathy on the part of the hearer for the objects of the speaker’s concern. Example: all of us cannot be famous, because all of us cannot be well known.
Appeal to force (ad baculum) When careful reasoning is replaced with direct or insinuated threats to cause the acceptance of some conclusion. Example: The President continues to have confidence in the Attorney General and I have confidence in the Attorney General and you ought to have confidence in the Attorney General, because we work for the President and because that’s the way things are. And if anyone has a different view of that, or any different motive, ambition, or intension, he can tell me about it because we’re going to have to discuss your status
Irrelevant conclusion(ignoratio elenchi) When the premisses miss the point, purporting to support one conclusion while in fact supporting or establishing another Example: “Veterans have alwys a strong voice in our government”. President Reagan said all too accurately, adding the non sequitur: “It’s time to give them the recognition they so rightly deserve.
Fallacies of ambiguity The mistaken arguments are formulated in such a way as to rely on shifts in the meaning of words or phrases, from their use in the premisses to their use in the conclusion. Five types of it: • Equivocation • Amphiboly • Accent • Composition • Division
Equivocation When the same word or phrase is used with two or more meanings, deliberately or accidentally, in the formulation if an Argument.
Amphiboly When one of the statements in an argument has more than one plausible meaning because of the loose or awkward way in which the words in that statement are combined.
Accent When a shift of meaning arises within an arguments as a consequence of changes in the emphasis given to its words or parts.
Composition This mistake is made: • When one reasons mistakenly from the attributes of a part to the attributes of the whole, and • When one reasons mistakenly from the attributes of individual member of some collection to the attributes of the totality of that collection Example: Since every ship is ready for battle, the whole fleet must be ready for battle.
Division This mistake is made: • when one reasons mistakenly from the attributes of a whole to the attributes of one of its parts, and • when one reason is mistakenly from the attributes of a totality of some collection of entities to the attributes of the individual entities themselves. Example: Humans are mortal. Socrates is a human. So Socrates is mortal.
1.Seeing that eyes and hand and foot and every one of our members has some obvious function, must we not believe that in like manner a human being has a function over and above these particular function? 2. But space is nothing but a re ation. For, in the first place, any space must consist of parts; and if the parts are not spaces, the whole is not space.
Thomas Carllyle said of Walt Whitman that he thinks he is a big poet because he comes from big country
