The liar paradox has perplexed philosophers, logicians, and mathematicians throughout history. Although it dates back to ancient Greece, it’s currently a subject of study and debate. We’re going to explore this paradox that’s defied logic and reason in depth. We’ll discover its meaning and its various proposed solutions.
From one simple sentence, all kinds of logical and philosophical theories have arisen, making this paradox even more enigmatic. How is it possible that truth and lies can be intertwined in such a complex way? How might it affect your daily life and your way of interacting with others? If you’re passionate about psychology and want to discover more about this intriguing topic, read on.
The oldest known version of the liar paradox (also known as the Epimenides paradox) was formulated by Epimenides of Crete. He was a Greek poet and prophet from the 6th century BC.
The liar paradox is as follows. Epimenides once claimed that all Cretans were liars. The paradox is that Epimenides was a Cretan himself. Therefore, if all Cretans were liars, then Epimenides was also a liar. But, if Epiminedes was a liar, then his statement that all Cretans were liars must be a lie. This would mean all Cretans told the truth which means Epimenides also told the truth. This means the statement that all Cretans were liars is both true and false. As you can see, it’s an enigma to which there appears to be no solution.
The oldest contradiction of the kind in question is that of Epimenides the Cretan, who said that all Cretans were liars and all other statements made by Cretans were indeed lies. Was this a lie?
Over time, this paradox has been formulated in various ways. The most popular claims that “This sentence is false”. The contradiction is the same as Epimenides’ sentence: if it’s true, it becomes false because its content is false. But, if it’s false, it becomes true because what it says is true.
The problem with the liar paradox
Logic has found three problems with this paradox. The first resorts to the law of the excluded middle. This rule maintains that, in a proposition or sentence, it’s only possible for there to be two options. Therefore, there are only two truth values: true and false.
In the case of the Epimenides paradox, following this principle, there’d be no possibility of a third option. So, is it true or is it false? And, what if it’s both at the same time? In that case, a logical contradiction arises, since a truth value can’t be assigned without arriving at a contradiction.
The second problem is self-referentiality. In other words, a sentence that talks about itself. In the paradox in question, Epimenides says himself that it’s false. But the underlying issue, according to different interpretations, is that a sentence can’t say anything about itself. Indeed, in this scenario, it’s the human being who says something, not the statement. In effect, whoever gives meaning to the sentence or to what’s said is the subject, not the sentence.
The third problem arises when we want to give truth to the sentence. In this sense, logic is being criticized as a discipline. That’s because, in everyday life, we don’t analyze everything we say. Rather, we state what we want and try to give it its own meaning.
Examples of the liar paradox
Epimenides’ contradictory statement formed the foundation of many other formulations that deal with the same problem. Here are a few:
- I’m a liar.
- I never tell the truth.
- This statement is false.
- The following sentence is false. The above sentence is true
The perplexity caused by this type of contradiction causes other similar specimens to be sought, to see if a resolution can be reached.
Is there a solution?
Despite multiple attempts by philosophers to find a solution, they’ve had no luck finding one. However, they’ve reached certain conclusions that encourage further thinking on this and other issues.
Some philosophers, such as Alfred Tarski, proposed a possible agreement to define the concept of truth and falsehood. According to him, the problem begins when there’s no detailed description of these values.
Others, such as Paul Grice, a 20th-century British philosopher, argue that one must understand the context in which language is used. For him, the paradox arises when it’s used in a decontextualized way.
Meanwhile, the great philosopher, Bertrand Russell proposed some solutions to the paradox. He suggested it was due to flaws in logic. Therefore, he suggested introducing words or propositions so that the problem of self-referentiality doesn’t occur.
In short, several solutions to the paradox have been attempted, but none have been satisfactory. Despite this, the philosophical contributions made to this contradiction served as a way to raise and problematize new issues.
An unsolved but fascinating problem
The liar paradox is one of the most challenging and fascinating puzzles in the world of logic. So much so that, throughout the centuries, many philosophers, mathematicians, and logicians have debated the subject. Even though they didn’t reach any solution, the study of the paradox has allowed evolution within the fields of logic and philosophy.
Moreover, its irresolution obliges us to continue examining concepts such as those of truth and falsehood. We need to consider the meaning we give to what’s been said and apply logical concepts to everyday life. After all, words and speaking are part of everyday life.