There are two styles of refutation：for some depend on thelanguage used，while some are independent of language.Those ways ofproducing the false appearance of an argument which depend on languageare six in number：they are ambiguity，amphiboly，combination,division of words，accent，form of expression.Of this we may assureourselves both by induction，and by syllogistic proof based onthis—and it may be on other assumptions as well—that this is thenumber of ways in which we might fall to mean the same thing by thesame names or expressions.Arguments such as the following depend uponambiguity.”Those learn who know：for it is those who know theirletters who learn the letters dictated to them”.For to ”learn” isambiguous; it signifies both ”to understand” by the use ofknowledge，and also ”to acquire knowledge”.Again，”Evils are good:
for what needs to be is good，and evils must needs be”.For ”whatneeds to be” has a double meaning：it means what is inevitable，asoften is the case with evils，too (for evil of some kind isinevitable)，while on the other hand we say of good things as wellthat they ”need to be”.Moreover，”The same man is both seated andstanding and he is both sick and in health：for it is he who stoodup who is standing，and he who is recovering who is in health：butit is the seated man who stood up，and the sick man who wasrecovering”.For ”The sick man does so and so”，or ”has so and so doneto him” is not single in meaning：sometimes it means ”the man who issick or is seated now”，sometimes ”the man who was sick formerly”.
Of course，the man who was recovering was the sick man，who really wassick at the time：but the man who is in health is not sick at the sametime：he is ”the sick man” in the sense not that he is sick now，butthat he was sick formerly.Examples such as the following dependupon amphiboly：”I wish that you the enemy may capture”.Also thethesis，”There must be knowledge of what one knows”：for it ispossible by this phrase to mean that knowledge belongs to both theknower and the known.Also，”There must be sight of what one sees：onesees the pillar：ergo the pillar has sight”.Also，”What you professto—be，that you profess to—be：you profess a stone to—be：ergo youprofess—to—be a stone”.Also，”Speaking of the silent is possible”:
for ”speaking of the silent” also has a double meaning：it may meanthat the speaker is silent or that the things of which he speaks areso.There are three varieties of these ambiguities and amphibolies:
(1) When either the expression or the name has strictly more thanone meaning，e.g.aetos and the ”dog”; (2) when by custom we usethem so; (3) when words that have a simple sense taken alone have morethan one meaning in combination; e.g.”knowing letters”.For eachword，both ”knowing” and ”letters”，possibly has a single meaning：butboth together have more than one—either that the letters themselveshave knowledge or that someone else has it of them.
Amphiboly and ambiguity，then，depend on these modes of speech.Uponthe combination of words there depend instances such as the following:
”A man can walk while sitting，and can write while not writing”.Forthe meaning is not the same if one divides the words and if onecombines them in saying that ”it is possible to walk—while—sitting”
and write while not writing].The same applies to the latter phrase,too，if one combines the words ”to write—while—not—writing”：forthen it means that he has the power to write and not to write at once;whereas if one does not combine them，it means that when he is notwriting he has the power to write.Also，”He now if he has learnthis letters”.Moreover，there is the saying that ”One single thingif you can carry a crowd you can carry too”.
Upon division depend the propositions that 5 is 2 and 3，and odd,and that the greater is equal：for it is that amount and more besides.
For the same phrase would not be thought always to have the samemeaning when divided and when combined，e.g.”I made thee a slave oncea free man”，and ”God—like Achilles left fifty a hundred men”.
An argument depending upon accent it is not easy to construct inunwritten discussion; in written discussions and in poetry it iseasier.Thus (e.g.) some people emend Homer against those whocriticize as unnatural his expression to men ou kataputhetaiombro.For they solve the difficulty by a change of accent,pronouncing the ou with an acuter accent.Also，in the passageabout Agamemnon”s dream，they say that Zeus did not himself say ”Wegrant him the fulfilment of his prayer”，but that he bade the dreamgrant it.Instances such as these，then，turn upon the accentuation.
Others come about owing to the form of expression used，when what isreally different is expressed in the same form，e.g.a masculine thingby a feminine termination，or a feminine thing by a masculine，or aneuter by either a masculine or a feminine; or，again，when aquality is expressed by a termination proper to quantity or viceversa，or what is active by a passive word，or a state by an activeword，and so forth with the other divisions previously” laid down.Forit is possible to use an expression to denote what does not belongto the class of actions at all as though it did so belong.Thus (e.g.)”flourishing” is a word which in the form of its expression is like”cutting” or ”building”：yet the one denotes a certain quality—i.e.
a certain condition—while the other denotes a certain action.In thesame manner also in the other instances.
Refutations，then，that depend upon language are drawn from thesecommon—place rules.Of fallacies，on the other hand，that areindependent of language there are seven kinds:
(1) that which depends upon Accident:
(2) the use of an expression absolutely or not absolutely but withsome qualification of respect or place，or time，or relation:
(3) that which depends upon ignorance of what ”refutation” is:
(4) that which depends upon the consequent:
(5) that which depends upon assuming the original conclusion:
(6) stating as cause what is not the cause:
(7) the making of more than one question into one.