Seeing History
Arguments from Silence

This is one of two principles that are often cited in Latin. The Latin phrase for this one is

argumentum ex silentio

or the "argument from silence." We may here notice how this phrase is used in applied history, and then consider what else may be implied when something is not mentioned in the texts.

Page from a Coptic Manuscript of the Gospel of Mark

Evidential Silence

"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. We might explore these concepts just a little.


The converse of the first point is that if newly discovered documents continue not to mention X, then the case for the non-existence of X is proportionately strengthened. This is what statisticians call a sampling question. We may take the question of early Chinese swords as an example:

Even that considered conclusion is technically a working hypothesis. But at some point, a hypothesis from silence properly comes to be seen as capable of bearing weight; of doing work in history.

Confucian Temple Housing the Tang Stone Classics

Arguments from silence can be strengthened by the presence of something (call it Y) which replaces the conjectural X. Thus:

In sum, the argument from silence, like all historical arguments, is always conjectural. But it is not, as some claim, a fallacy. It is the correct default inference from silence. That inference can be strengthened by relevant evidence of a positive kind, or by the continued silence of further evidence.

Étienne Trocmé said it about right, in the Preface to his book The Childhood of Christianity:

There is no reason why new documents should not appear one day. So my conclusions are provisional and are always open to modification. However, it should be noted that the ancient libraries and archaeological sites which since the middle of the last century have given us so many unpublished documents, and very old manuscripts known hitherto only from later copies have now been the object of very thorough investigations. So the probability of new sensational discoveries is low. The account which follows may thus be regarded as relatively trustworthy, to the degree that it interprets the available documents correctly.

It is indeed a probability estimate. A statistical estimate. In certain well-defined situations, there is a precise point at which silence, or nonoccurrence, becomes statistically significant:

You first have to define how certain you want to be, but taking the conventional level of "99% certain," the answer is: after 7 consecutive tosses of Heads, it is 99% certain that something is wrong with the situation. Our advice would be to quit playing at that point. The hypothesis of honesty is no longer tenable.

Not To Be Said

Social Silence

As always, we need to be aware, not only of the numbers, but of the culture behind the numbers. There are various reasons, other than literal nonexistence, why some item of culture is not, or seems not to be, mentioned in the texts of the time. Such situations do not imply nonexistence.

These are among the cautions and considerations. A serious argument from silence will take them into account. But the argument from silence to nonexistence remains in principle a valid inference; the least unlikely conclusion to be drawn from the facts presently at hand.

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17 Dec 2006 / Contact The Project / Exit to Outline Index Page