There are two distinct ways in which the Fallacia Consequentis may be employed. The predicate may be an universal, comprehending the subject: because animal always goes along with man, it is falsely inferred that man always goes along with animal; or it is falsely inferred that not-animal always goes along with not-man. The fallacy is solved when this is pointed out. The last inference is only valid when the terms are inverted; if animal always goes along with man, not-man will always go along with not-animal.[121]
[121] Ibid. xxviii. p. 181, a. 22-30. ἀνάπαλιν γὰρ ἡ ἀκολούθησις.
If the sophistical refutation includes more premisses than are indispensable to the conclusion, the respondent, after having satisfied himself that this is the fact, will point out the mal-procedure of the questioner, and will say that he conceded the superfluous premiss, not because it was in itself probable but, because it seemed relevant to the debate; while nevertheless the questioner has made no real or legitimate application of it towards that object.[122] This is the mode of solution applicable in the case of the Fallacies coming under the head Non Causa pro Causâ.[123]
[122] Soph. El. xxix. p. 181, a. 31-35.
[123] Schol. p. 318, a. 36, Br.
Where the sophistical questioner tries to refute by the Fallacia Plurium Interrogationum (i.e., by putting two or more questions as one), the respondent should forthwith divide the complex question into its component simple questions, and make answer accordingly. He must not give one answer, either affirmative or negative, to that which is more than one question. Even if he does give one answer, he may sometimes not involve himself in any contradiction; for it may happen that the same predicate is truly affirmable, or truly deniable, of two or more distinct and independent subjects. Often, however, the contrary is the case: no one true answer, either affirmative or negative, can be given to one of these complex questions: the one answer given, whatever it be, must always be partially false or inconsistent.[124] Suppose two subjects, A and B, one good, the other bad: if the question be, Whether A and B are good or bad, it will be equally true to say — Both are good, or, Both are bad, or, Both are neither good nor bad. There may indeed be other solutions for this fallacy: Both or All may signify two or more items taken individually, or taken collectively; but the only sure precaution is — one answer to one question.[125]
[124] Soph. El. xxx. p. 181, a. 38: οὔτε πλείω καθ’ ἑνὸς οὔτε ἓν κατὰ πολλῶν, ἀλλ’ ἓν καθ’ ἑνὸς φατέον ἢ ἀποφατέον.
[125] Ibid. b. 6-25.
Suppose that, instead of aiming at a seeming refutation, the Sophist tries to convict the respondent of Tautology. The source of this embarrassment is commonly the fact that a relative term is often used and conveys clear meaning without its correlate, though the correlate is always implied and understood. The respondent must avoid this trap by refusing to grant that the relative has any meaning at all without its correlate; and by requiring that the correlate shall be distinctly enunciated along with it. He ought to treat the relative without its correlate as merely a part of the whole significant expression — as merely syncategorematic; just as ten is in the phrase — ten minus one, or as the affirmative word is in a negative proposition.[126] Thus he will not recognize double as significant by itself without its correlate half, nor half without its correlate double; although in common parlance such correlate is often understood without being formally enunciated.
[126] Soph. El. Xxxi. p. 181, b. 26: οὐ δοτέον τῶν πρός τι λεγομένων σημαίνειν τι χωριζομένας καθ’ αὑτὰς τὰς κατηγορίας.