TIP of the day (logic): Argument from silence aka argumentum ex silentio

MJ. Smith

"The reality is there is not one shred of secular evidence there ever was a Jesus Christ. Jesus Christ and Christianity is a modern religion. And Jesus Christ is a compilation from other gods: Osiris, Mithras, who had the same origins, the same death as the mythological Jesus Christ."

from The Thinking Atheist

An argument from silence is often a fallacy - assuming something to be true because your opponent has said nothing to the contrary is fallacious.

However, it is a valid, albeit weak, argument in history. For example, if I lived 1000 years in the future I might read the diaries of Lewis and Clark and infer that The Dalles Dam (hydroelectric plant) had not yet been built because they did not mention it. There are three conditions that must be met.

John Lange provided the basic structure for the analysis of arguments from silence based on three components:

• An extant document D in which no reference to an event E appears.

• It is known that the intention of the author of document D was to provide an exhaustive list of all the events in the class of events to which E belongs

• Event E is assumed to be a type of event which the author of D would not have overlooked, had the event taken place.

Given that the dam is at the site of a portage, it is reasonable to expect that Lewis and Clark would have referenced a dam if it were present as it would radically change the nature of the portage.

So where does that leave Ellen Johnson? She must show all of the following to make her weak historical argument from silence - weak because all arguments from silence are by nature weak.

• all the secular documents in any language that survive describing the period of Jesus' life or closely thereafter do not have a reference to the life of Jesus of Nazareth
• at least one of these documents' author intended to write exhaustively on a topic that would include the life of Jesus of Nazareth
• the life of Jesus of Nazareth would have clearly been of sufficient importance to that author that it would be included had the author known of it

These are not easy criteria to meet as is shown on the history page "Seeing History | Argument from Silence". And how difficult is it to annul the argument? From the article just mentioned:

[quote]

"Silence" means that the thing in question (call it X) is not mentioned in the available documents. If it were mentioned, then with the usual qualifications it would be proved to exist. Since X is not mentioned, X cannot be proved to exist. A natural further inference from this evidence is that X did not exist. The basic point is that if X did not in fact exist, then the only trace which that fact could leave, in the evidence, is the silence of the evidence as to X. At the same time, any such conclusion must be provisional. If documents are later found that do mention X, then X is after all proved to exist. A single positive may overturn any number of negatives. A single sound refutes all silences.

The possibility of such a future positive can never be ruled out. But until it occurs, the non-existence of X is the best inference from the absence of X in the evidence. The strength of that inference in a given case will depend on (1) how many documents there are, or in statistical terms how large the sample is, and, in literary terms, (2) how likely the thing is to have been mentioned in documents of that type in the first place.

Note we only need a single counter-example for the inference to be false.  The site Bible Think provides us with a list of potential counter-examples, limited here to secular sources as Johnson qualified her statement.

Roman Writers:-

• Flavius Josephus:  Josephus wrote “Antiquities of the Jews” in about 94AD. In it he mentions Jesus twice, once in passing and one more time which has probably been corrupted to some extent by later scribes.
• Pliny the Younger:  In the course of his governorship of Bithynia in 112AD Pliny wrote a letter to the emperor asking about Christians in his province.
• Tacitus:  Tacitus wrote a history of the early emperors in c116AD. In his account of Nero he mentions the persecution of Christians and includes a brief account of the start of Christianity: “Christ, the originator of the name [Christian] suffered the death penalty in the reign of Tiberius by sentence of the governor Pontius Pilate.
• Suetonius:  Suetonius wrote another history in c120AD. This contains a small reference to Christians and another reference which may be to Jesus and which confirms a detail in Acts.
• Lucian of Samosata:  In  c170 Lucian wrote a satire on a Greek philosopher in which the philosopher spent some time with Christians. In the course of this, Jesus is mentioned.
• Celsus:  Celsus was a philosopher who wrote a treatise against Christianity (c180AD) in which he mentions Jesus.

In addition to these there are two writers where there are problems in terms of date or the nature of the reference:-

• Mara bar-Sarapion: wrote a letter which refers to the “wise king” executed by the Jews
• Thallus: Wrote a history in the mid first century AD which mentions the darkness at Jesus’ crucifixion. The work is lost but was quoted by the second century Julius Africanus.
• Phlegon: Wrote an astronomical treatise which mentions the darkness at Jesus’ crucifixion.

The burden of proof is on Johnson to show that none of these constitute the "single sound" that deflates her argument.