Consensus without Coherence

This is about some of the theories of truth, triggered by the previous post, "Concord without Confusion", during the writing of which this author discovered the consensus theory of truth, and marveled greatly.

The consensus theory of truth is defined on Wikipedia as, "the process of taking statements to be true simply because people generally agree upon them."

The author prefers the correspondence theory of truth in which, according to Wikipedia, the truth of a statement "is determined only by how it relates to the world and whether it accurately describes (i.e., corresponds with) that world."

A definition of truth can be found in the Doctrine and Covenants, in section 93 verse 24, which says that, "truth is knowledge of things as they are, and as they were, and as they are to come". Clearly this aligns with the correspondence theory of truth.

On the other hand when "people generally agree" on something, we are dealing with beliefs, and beliefs don't necessarily have anything to do with how things really are, were, or will be. 

Even worse, there isn't just one consensus. There are many, depending on which people you are talking about. It seems obvious that any given consensus might not align at all with what is actually true.

Two timelines: an illustration

Ironically, the author here assumes there is general agreement that our current time follows a "dark ages" and then an enlightenment. 

How did we (humanity) get to where we are now? There is no unanimity, and so no general agreement on this question. Let's look at a couple of different sequences that each have a large number of people who generally agree on them.

There is one consensus that our present time might have originated from a sequence of events like this:

1. The big bang happened
2. Stars, planets, and life happened
3. Humans invented^✨ a notion of god to explain the existence of humanity
4. During the enlightenment, humans realized^✨ that this sequence is a sufficient explanation
5. Here we are

There is another consensus that our present time came through this sequence of events:

1. God exists
2. God created stars, planets, and life
3. God revealed himself^🔆 to some humans explaining the existence of humanity
4. Around the time of the enlightenment, God revealed himself^🔆 to Joseph Smith
5. Here we are

Two world views that are mutually inconsistent, despite each having numerous adherents, and thus each a consensus. 

There can be little disagreement about item 5. We are here for sure.

The fourth item is represented by, in the first sequence, humanism (see the original humanist manifesto of 1933 (signed by over 30 eminent individuals)). 

The fourth item is represented by, in the second sequence, The Church of Jesus Christ of Latter-day Saints (see Joseph Smith -- History (dating to the early 1800's)).

In both sequences, the third item happened many times and in many places. 

There is a timing difference for the second item, but those things obviously exist now. 

The first item is an article of faith in both sequences.

Coherence theory of truth

This is a somewhat technical theory (at least as the author learned about it during his doctoral studies) from the work of Nicholas Rescher, as described in the 1982 edition of his book, The Coherence Theory of Truth.

It starts off with the premises that 1) people believe contradictory things, and 2) that pure logic would allow us to prove that anything is true (given that starting point), and 3) finally shows how to construct sets of coherent statements using pure logic. In other words, it is a way of getting at the truth implied by contradictory beliefs.

What about Science?

The consensus theory of truth seems to be related to the logical fallacy of "appeal to authority". If enough people with a good enough reputation believe something to be true, then the claim is made that that something is in fact true.

A strange thing then happens. When a consensus is broad enough, its adherents tend to assume that people who don't believe in it are uneducated or irresponsible. Contempt can then be had for whatever consensus those people espouse. The phrase "trust the science" is an example of this, as it is commonly used these days.

Science is one part careful observation and another part coming to consensus on what the observations mean. The first part can be done rigorously and is repeatable: different observers obtain the same results. The second part is a social activity, rife with factions, disagreements, and personalities. The first part assumes the correspondence theory of truth. The second part depends on the consensus theory of truth.

Obtaining coherence, or agreement, between one consensus and another can be very difficult if not impossible. We end up agreeing to disagree in the best outcome, or contending vigorously (and even contemptuously) in the worst outcome.

The author proposes no fix for this problem but is just pointing it out so that we can think about it clearly, and hopefully rationally and without animus.

Notes

Quotes from Wikipedia were obtained on the day of this writing.