Veritas, the Roman goddess of truth.

Truth (from West Saxon triewd; Greek alethia; Latin veritas) is to mean in accordance with reality.


1   Etymology

from Latin verus "true"
very - true verify - make true

"in invo veritas" is a Latin phrase that mens "in wine truth" suggesting that a person under the influence of alcohol is more likely to speak their hidden thoughts and desires.

2   History

Most people are interested in the truth of particular proposition. Philosophers care about the nature of truth. One question is whether it's the same notion across different topics. For example, if say "Rembrandt is a great artist" and "I had eggs for breakfast" is that the same kind of truth?

2.1   Correspondence theory

Correspondence theory is a theory of truth given by Aristotle which states that truth is correspond to the fact; that is, a proposition is true if facts prove it. This has several problems however. For one, facts cannot prove counterfactuals. For example, if I state "I didn't have bacon for breakfast" and if I didn't have bacon for breakfast, we cannot prove my statement was true. Similarly, we cannot decide the truth value of statements like "if you touch the oven, you will get burned".

The second problem is that facts change. For example, the statement "The Eiffel Tower is in Paris" can be made false if we moved it to another city.

It also has problem dealing with matters of aesthetics, which does not seem to be based in facts, and mathematics, which is also not based in facts, but artificial proofs.

Correspondence theory works for observable things, but cannot handle propositions which do not deal with perception.

2.2   Coherence theory

All truth is coherence of ideas. The theory was attractive because it was antirealist.

`Bertrand Russel`_ famously objected.

3   Technique

There are several techniques to do this.

Arguably, the 1800s were the Golden Age of schemes. The term "confidence man" or "con man" was probably coined midcentury

A new study in the Journal of Consumer Research might have the answer. Researchers found that shoppers deal with pricing information differently when prices feature round numbers ("5"), as opposed to non-round ones ("4.99"). When something costs $100, consumers tend to rely on their feelings, whereas when something has an irregular price—such as $98.67—consumers have to use reason to compute whether it's a good price. Monica Wadhwa and Kuangjie Zhang, assistant professors of marketing at INSEAD and at Nanyang Business School respectively, conducted five experiments to test this. They found that the prices of different types are evaluated in different ways. For example, products that are recreational or luxurious benefit from rounded prices: Consumers were more inclined to buy a bottle of champagne when it was priced at $40.00 rather than at $39.72 or $40.28. However, for purchases that are utilitarian—a calculator, in this experiment—participants were more likely to buy at the higher non-rounded price. In another experiment, participants were told that a camera was purchased for leisure (a family vacation) or for a class project. They preferred rounded prices when it was for vacation, and non-rounded prices for class projects.

The paper is called "This Number Just Feels Right: The Impact of Roundedness of Price Numbers on Product Evaluations" in the Journal of Consumer Research.