{"id":5040,"date":"2021-10-21T10:31:50","date_gmt":"2021-10-21T08:31:50","guid":{"rendered":"http:\/\/icar.cnrs.fr\/dicoplantin\/?p=5040"},"modified":"2025-06-23T16:51:01","modified_gmt":"2025-06-23T14:51:01","slug":"ignorance-e","status":"publish","type":"post","link":"https:\/\/icar.cnrs.fr\/dicoplantin\/ignorance-e\/","title":{"rendered":"Ignorance"},"content":{"rendered":"

Argument From IGNORANCE<\/span><\/h1>\n

1. Argument from Ignorance and the Legitimacy of Doubt<\/span><\/h2>\n

Locke defines the argument from ignorance [1] as one of the four basic forms of argument, see collections 2<\/a>:<\/p>\n

Secondly, another way that men ordinarily use to drive others, and force them to submit to their judgment, and receive the opinion in debate, is to require the adversary to admit what they allege as a proof or to assign a better. And this I call argumentum ad ignorantiam.<\/em> ([1690]; Vol. II, p. 410-411)<\/span><\/p>\n

This argument is considered fallacious:<\/p>\n

It proves not another man to be in the right way, nor that I ought to take the same way, because I know not a better.\u00a0(Id.<\/em>, p. 411)<\/span><\/p>\n

The following dialogue schematizes a situation in which S1<\/strong>‘s conclusion is based\u00a0 on S2<\/strong>‘s ignorance:<\/p>\n

S11<\/sub><\/strong>\u00a0 – A<\/strong>, therefore C<\/strong><\/span>
\nS21<\/sub><\/strong> \u00a0 – This is a bad argument. I do not accept that<\/em> A<\/strong> proves<\/em> C<\/strong>.<\/span>
\nS12<\/sub><\/strong>\u00a0 – Do you have any reason to conclude anything other than<\/em> C<\/strong>?
\nDo you have a better argument for<\/em> C<\/strong>?<\/span>
\nS22<\/sub><\/strong> \u00a0 – No.
\n<\/em>S13<\/sub><\/strong> \u00a0 – Then you must accept my proof and conclusion.<\/em><\/span><\/p>\n

(i) First round<\/strong>: S11<\/sub><\/strong> suggests the justified proposition C<\/strong>.<\/span><\/p>\n

(ii) Second round<\/strong>: S21<\/sub><\/strong> refuses to ratify the claim C<\/strong>.<\/span><\/p>\n

(iii) Third round<\/strong>: S12<\/sub><\/strong> asks S2<\/strong> to explain his reasons for doubt. According to the conversation principle which requires justification for non-preferred second turns, S1<\/strong> is perfectly justified in asking for an explanation. S2 <\/strong>could respond by:<\/span><\/p>\n

(a)<\/strong> refuting S11<\/sub><\/strong>‘s argument outright, or\u00a0 raising objections to it;<\/span>
\n(b)<\/strong> constructing a counterargument that provides what Locke calls \u201ca better proof.\u201d
\nSince the text does not specify the conclusion, so the following two cases can be assumed:<\/span><\/p>\n

(b1) inferring from A<\/strong> something different from C<\/strong>;<\/span>
\n(b2) providing a \u201cbetter proof\u201d than A<\/strong> for C<\/strong>.<\/span><\/p>\n

(iv) Fourth turn:<\/strong> S22<\/sub><\/strong> admits that he cannot elaborate on (a), (b1) or (b2).<\/span><\/p>\n

(v) Fifth turn<\/strong>: S1<\/strong> may:<\/span><\/p>\n

(a)<\/strong> acknowledge S2<\/strong>\u2019s reluctance, while maintaining his argumentation: \u201cOkay, this is not a very good argument, but it is interesting, In fact, it is the only one we have.<\/em>\u201d<\/span>
\n(b)<\/strong> Ask S2<\/strong> to accept his argument (A, C<\/strong>), and use S2<\/strong> inability as second-order evidence to strengthen to his previous argument A<\/strong>. This would be an ad ignorantiam<\/em> fallacy, even if his previous argument is not so bad.<\/span><\/p>\n

A pure ad ignorantiam<\/em> fallacy would be based solely on the partner’s failure \u201cto assign a better [proof]\u201d. In a conversation, when S21<\/sub><\/strong> does not ratify S11<\/sub><\/strong>\u2019s turn, this situation prompts S1<\/strong> to clarify and elaborate on his proposal. S1<\/strong>‘s crude dismissal seems\u00a0 too abrupt: \u201cSince you can’t articulate anything against my argument,<\/em> you must accept it in its entirely.<\/em>\u201d
\nFrom S2<\/strong>\u2019s perspective, this situation also seems bizarre, a borderline case, where S2<\/strong> only has his inner conviction to oppose the argument. Under normal conditions, a conversationalist\u2013and a fortiori a dialectician\u2013knows how to elaborate on a strong inner conviction. Locke seems to ascribe a radical clause of conscience to S2<\/strong>.<\/p>\n

Leibniz moderates Locke’s radical position:<\/p>\n

The argument ad ignorantiam<\/em> is valid in cases of presumption where it is reasonable to hold to an opinion till the contrary is proven. ([1765], p. 576)<\/span><\/p>\n

Presumption concerns the burden of proof<\/a>. Although S1<\/strong>‘s presumption may be exaggerated and misleading, his argument still creates a preference in this area. In practice we can adhere to this preference until something else is proven.
\nThis \u201cfor want of anything better<\/em>\u201d reasoning seems to be the standard in practical argumentation when a decision must be made and a possibly urgent action must be taken:<\/p>\n

S1i<\/sub><\/strong>: \u00a0\u00a0\u00a0 \u2014 On such-and-such a basis, I propose <\/em>1) that we take such-and-such a disposition;
\n<\/em>2) that we explore such-and-such a hypothesis<\/em>. Now, the floor is yours.<\/em><\/span><\/p>\n

S2: \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 [Long silence]<\/span><\/p>\n

S1j<\/sub><\/strong> \u00a0\u00a0\u00a0 \u2014 Nothing to say? Silence means agreement.
\n<\/em>1) In the absence of objection, my proposal is adopted.
\n<\/em>2) In the absence of any other hypothesis, mine will serve as the working hypothesis.<\/em><\/span><\/p>\n

It is difficult to disagree with S1j<\/sub><\/strong>\u2019s conclusions. He does not claim that his proposal is the only viable one, nor that his hypothesis is true.<\/p>\n

2. Ignorance and the Principle of the Excluded Middle<\/span><\/h2>\n

Regardless of the quality of the argument, an argument from ignorance can be defined as an illegitimate application of the principle of the excluded middle.<\/p>\n

P<\/strong> is true, because you cannot prove that it is false.<\/span><\/p>\n

The argument is inconclusive. If we consider that \u201cnot-P<\/strong> is not proved\u201d is equivalent to \u201cnot-(not-P)<\/strong>\u201d, then we can apply the principle of the excluded middle and conclude that P is true<\/strong>. However, the two negations are not of the same kind: \u201cnot-P<\/strong> is not proved\u201d does not mean \u201cnot-P<\/strong> is false\u201d, which would confuse what is true (alethic) with what is knowable (epistemic), see absurd<\/a>.<\/p>\n

3. Ignorance, Burden of Proof, Precautionary Principle<\/span><\/h2>\n

I am innocent, because you cannot to prove that I am guilty.<\/span>
\nYou are guilty because you cannot prove your innocence.<\/span><\/p>\n

Admitting that P<\/strong> is true, or acting \u201cas if\u201d it were true in the absence of proof that it is false is a decision incumbent upon the institution empowered to discuss and decide such matters in the relevant field. In the law, the presumption of innocence places the burden of proof on the prosecution and gives the benefit of the doubt to the accused.<\/p>\n

The Precautionary Principle<\/strong>
\nIn debates about the safety or toxicity of new products, decisions must be made in situations of insufficient knowledge. The presumption of safety<\/em> would be:<\/p>\n

The product may be toxic, but this has not been proven. Therefore, it has no toxic effects \/ it is deemed safe.<\/span><\/p>\n

The precautionary principle<\/em> is easiest to refute when maximized:<\/p>\n

Any new product is presumed to be toxic and remains banned until its safety is proven.<\/span><\/p>\n

In its most common form, the principle simply reverses the burden of proof:<\/p>\n

The precautionary principle<\/em> (or precautionary approach<\/em>) to risk management states that when an action or policy is suspected of causing harm to the public, or the environment, in the absence of scientific consensus (that the action or policy is not harmful), the burden of proof that it is not<\/em> harmful falls on those taking an action that may or may not pose a risk.<\/span>
\nWikipedia, Precautionary Principle<\/em><\/span><\/p>\n

4. Argument from Ignorance and Argument from Silence<\/span><\/h2>\n

See silence<\/a><\/p>\n

\n[1] Latin ad ignorantiam<\/em> argument ignorantia<\/em>, \u201cignorance\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Argument From IGNORANCE 1. Argument from Ignorance and the Legitimacy of Doubt Locke defines the argument from ignorance [1] as one of the four basic forms of argument, see collections 2: Secondly, another way that men ordinarily use to drive others, and force them to submit to their judgment, and receive the opinion in debate, […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-5040","post","type-post","status-publish","format-standard","hentry","category-non-classe"],"_links":{"self":[{"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/posts\/5040","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/comments?post=5040"}],"version-history":[{"count":22,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/posts\/5040\/revisions"}],"predecessor-version":[{"id":14433,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/posts\/5040\/revisions\/14433"}],"wp:attachment":[{"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/media?parent=5040"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/categories?post=5040"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/icar.cnrs.fr\/dicoplantin\/wp-json\/wp\/v2\/tags?post=5040"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}