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is derived from the Topics or middle Terms which are used in them, tho they are called an Address to our Judgment, our Faith, our Ignorance, our Profession, our Modesty, and our Pasions.
1. If an Argument be taken from the Nature or Existence of Things, and addressed to the Reason of Mankind, it is called Argumentum ad Judicium.
2. When it is borrowed from some convincing Testimony, it is Argumentum ad Fidem, an Address to our Faith.
3. When it is drawn from any insufficient Medium whatsoever, and yet the Opposer has not Skill to refute or answer it, this is Argumentum ad Ignorantiam, an Address to our Ignorance.
4. When it is built upon the profest Principles or Opinions of the Person with whom we argue, whether these Opinions be true or false, it is named Argumentum ad Hominem, an Address to our profest Principles. St. Paul often uses this Argument when he reasons with the Jews, and when he says, I speak as a Man.
5. When the Argument is fetched from the Sentiments of some wise, great, or good Men, whose Authority we reverence and hardly dare oppose, it is called Argumentum ad Verecundiam, an Address to our Modesty.
6. I add finally, when an Argument is borrowed from any Topics which are suited to engage the Inclinations and Passions of the Hearers on the Side of the Speaker, rather than to convince the Judgment, this is Argumentum ad Pasiones, an Address to the Passions ; or if it be made publickly, it is called ad Populum, or an Appeal to the People.
After all these Divisions of Syllogism or Argument arising from the middle Term, there is one Distinction proper to be mentioned which arifes from the Premises. An Argument is called uniform when both the Premisses are derived from the same Springs of Knowledge, whether it be Sense, Reason, Consciousness, buman Faith, or divine Faith: But when the two Premiffes are derived from different Springs of Knowledge, it is called a mixt Argument.
Whether the Conclusion must be called Human or Divine, when one or both Premiffes are Matters of Divine Faith but the Conclusion is drawn by buman Reason, I leave to be disputed and determined in the Schools of Theology.
Thus the second Chapter is finished, and a particular Account given of all the chief Kinds or Syllogisms or Arguments which are made use of among Men, or treated of in Logick, together with special Rules for the Formation of them, as far as is necessary.
If a Syllogism agree with the Rules which are given for the Construction and Regulation of it, it is called a true Argument : If it disagree with these Rules, it is a Paralogism, or false Argument: But when a falfe Argument puts on the Face and Appearance of a true one, then it is properly called a Sophism or Fallacy which shall be the Subject of the next Chapter.
The Doctrine of Sophisms.
ROM Truth nothing can really follow but
what is true : Whenfoever therefore we find a false Conclusion drawn from Premisses which seem to be true, there must be some Fault in the Deduction or Inference; or else one of the Premiffes is not true in the Sense in which it is used in that Argument.
When an Argument carries the Face of Truth with it, and yet leads us into Mistake, it is a Sophism; and there is some Need of a particular Description of these fallacious Arguments, that we may
with more Ease and Readiness detect and solve them.
Of several Kinds of Sophisms, and their Solution.
S the Rules of right Judgment and of good
often coincide with each other, so the Doctrine of Prejudices, which was treated of in the second Part of Logick, has anticipated a great deal of what might be said on the Subječt of Sophisins ; yet I shall mention the most remarkable Springs of false Argumentation, which are reduced by Logicians to some of the following Heads.
1. The first sort of Sophisın is called Ignoratio Elenchi, or a Mistake of the Question ; that is, when something else is proved which has neither any necessary Connection or Inconfiftency with the Thing enquired, and consequently gives no Determination to the Enquiry, tho it may seem at first Sight to determine the Question ; as, if any
should conclude that St. Paul was not a native Jew, by proving that he was born a Roman ; or if they should pretend to determine that he was neither Roman, nor Jew, by proving that he was born at Tarsus in Cilicia : These Sophisms are refuted by shewing that all these three may be true ; for he was born of Jewish Parents in the City of Tarsus, and by some peculiar Privilege granted to his Parents, or his native City, he was born a Denizen of Rome. Thus there is neither of these three Characters of the Apostle inconsistent with each other, and therefore the proving one of them true does not refute the others.
Or if the Question be proposed, Whether Excess of Wine can be hurtful to him that drinks it, and the Sophister should prove that it revives bis Spirits, it exhilarates his Soul, it gives a Man Courage, and makes him strong and ačtive, and then he takes it for granted that he has proved his Point.
But the Respondent may easily shew that tho? Wine may do all this, yet it may be finally burtful both to the Soul and Body of him that drinks it to excefs.
Disputers when they grow warm are ready, tu run into this Fallacy: They dress up the Opinion of their Adversary as they please, and ascribe Sentiments to him which he doth not acknowledge ; and when they have with a great deal of Pomp attacked and confounded these Images of Straw 4.
of their own making, they triumph over their Adversary as tho' they had utterly confuted his Opinion.
It is a Fallacy of the same kind which a Disputant is guilty of when he finds that his Adversary is too hard for him, and that he cannot fairly prove the Question first proposed; he then with Slyness and Subtilty turns the Discourse aside to fome other kindred Point which he can prove, and exults in that new Argument wherein his Opponent never contradicted him.
The Way to prevent this Follacy is by keeping the Eye fixt on the precise Point of Dispute, and neither wandring from it ourselves, nor suffering our Antagonist to wander from it, or substitute any, thing else in its Room.
II. The next Sophism is called Petitio Principii, or a Supposition of what is not granteil; that is, when any Proposition is proved by the fame Proposition in other Words, or by something that is equally uncertain and disputed : As if any one undertake to prove that the human Soul is extended throm all the Parts of the Body, because it resides in every Member, which is but the fame Thing in other Words. Or if a Papist should pretend to prove that his Religion is the only Catholick Religion, and is derived from Christ and his Apostles, because it agrees with the Doctrine of all the Fathers of the Church, all the holy Martyrs, and all the Christian World throughout all Ages : Whereas this is a great Point in Conteft, whether their Religion does agree with that of all the Anticnts and the primitive Christians, or no.
III. That Sort of Fallacy which is called a Circle is very near akin to the Petitio Principii ; as,