A very brief overview of the Historical Method

When reading history, I sometimes find myself wondering how historians can be so sure about what really took place hundreds or thousands of years ago. This usually happens when I’m reading about an uncertain time in the past where there’s no clear historical consensus.

As a result, I thought it’d be a good idea to study the historical method that historians use so that I can be better equipped in the future when considering opposing historical narratives.

Historical sources give us clues about the past

History is the study of the past and we only know of the past because of historical sources. A historical source is anything that can tell us about what happened in the past. Examples include artifacts such as documents, books, paintings, or manuscripts.

Such sources can be classified into two main groups: primary sources and secondary sources. Primary sources are usually artifacts that were created at the time under study whilst secondary sources typically build on top of primary sources.

For example, a Roman coin that was made at the time of the Romans is a primary source, whilst a 19th-century drawing of a Roman coin is a secondary source. A book written about the Roman emperor Augustus during his lifetime is a primary source, whilst a book written about him in the 21st century is a secondary source.

Primary sources are usually preferred because they’re closer to the time of study and less prone to being distorted over time as memory fades or new cultural or personal biases are developed.

Source criticism – determining the reliability of sources

Once we find a bunch of relevant sources, how can we determine which are reliable and which aren’t?

I’m sure there’s more to it but here are a number of characteristics that make for a credible source. The more of these characteristics a source has, the more reliable it is.

The source is close to the event

The closer in time and place the source is to the event which it describes, the more we can trust it to give an accurate description of what really happened. A long lapse in time can distort people’s fallible memories or introduce personal bias as their beliefs and values change.

Multiple independent sources contain the same message

If multiple sources seem to confirm the same message, then credibility is strongly increased. For example, 100 separate eyewitness accounts of the appearance of a resurrected Jesus makes the event more credible than say only 3 eyewitness accounts. Also, the less contradiction found in other independent sources, the more credible the source.

Originality can be trusted

Any given source may be forged or corrupted over time. The more reason we have to consider the source original and unchanged, the more reliable.

No bias or personal interests

If it can be demonstrated that the source’s publisher or a witness account has no direct interest in creating bias, the credibility of the message is increased. Even better if it can be demonstrated that the source’s message would have been disadvantageous to the source’s publisher.

For example, if giving an eye witness account for an event places the witness’s life in danger with no obvious potential for gain, then it becomes less likely that the witness would make it up (though not a guarantee).

Formulating historical hypotheses from sources

Once all the important sources have been examined, we can form hypotheses based on historical reasoning. I suppose it’s sort of similar to being a detective – we have to figure out what happened based on the given data and evidence.

In the ideal world, we’d have many reliable sources and they’d all support the same hypothesis. Unfortunately, that’s not always the case, so what do we do in such a situation? We do a bit of abductive reasoning and make a good guess!

Inference to the best explanation

In his book Justifying Historical Descriptions, C. Behan McCullagh gives us seven conditions for forming hypotheses that offer the best explanation for a set of historical sources and observations.

  1. The statement, together with other statements already held to be true, must imply yet other statements describing present, observable data. (We will henceforth call the first statement ‘the hypothesis’, and the statements describing observable data, ‘observation statements’.)
  2. The hypothesis must be of greater explanatory scope than any other incompatible hypothesis about the same subject; that is, it must imply a greater variety of observation statements.
  3. The hypothesis must be of greater explanatory power than any other incompatible hypothesis about the same subject; that is, it must make the observation statements it implies more probable than any other.
  4. The hypothesis must be more plausible than any other incompatible hypothesis about the same subject; that is, it must be implied to some degree by a greater variety of accepted truths than any other, and be implied more strongly than any other; and its probable negation must be implied by fewer beliefs, and implied less strongly than any other.
  5. The hypothesis must be less ad hoc than any other incompatible hypothesis about the same subject; that is, it must include fewer new suppositions about the past which are not already implied to some extent by existing beliefs.
  6. It must be disconfirmed by fewer accepted beliefs than any other incompatible hypothesis about the same subject; that is, when conjoined with accepted truths it must imply fewer observation statements and other statements which are believed to be false.
  7. It must exceed other incompatible hypotheses about the same subject by so much, in characteristics 2 to 6, that there is little chance of an incompatible hypothesis, after further investigation, soon exceeding it in these respects.


So in summary, the very dumbed-down version of how we can use the historical method to study a particular time in the past is something like this:

  1. Read about the key hypotheses offered by historians.
  2. Identify all the key historical sources. Step 1 should make these known.
  3. Evaluate these sources for reliability. Refer to the Source Criticism section from above on what makes for a reliable source.
  4. Re-evaluate the hypotheses from step 1 based on your own evaluation of the sources and then make an informed decision on which seems most plausible.

TODO: simplify the language of McCullagh’s seven conditions.

Sajad Torkamani

Hello! My name is Sajad. I’m a software developer at Nationwide and an aspiring entrepreneur. Originally from Afghanistan, I moved to London at an early age and have been living here for the past 20 years.

This is my personal website where I blog mostly about programming with occasional thoughts on a bunch of other things. I write mainly for my own benefit as I find that writing helps clarify my otherwise very confused thoughts.

Get in touch: sajadtorkamani1@gmail.com