1.1 Issues with Respect to Truth
The Greek philosopher, Aristotle
(384 BCE−322 BCE), one of the earliest and most influential philosophers in the history of Western thought, explains truth and falsity like this: “To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true.”1
Notice that Aristotle defines truth and falsity in terms of what we say
. We communicate by using combinations of words that form statements
. Some statements are questions like “Are you feeling ill?” and some statements are warnings like “Be careful!” Notice that such statements are not asserting that something is true or false. Statements that do propose that a certain idea
is true or false are propositions
. The following are examples of propositions: “brown is a color,” “some dogs are brown,” and “all birds are brown.” The same proposition can be expressed by different statements. Thus, the English statement “brown is a color,” the Spanish statement “el marrón es un color,” and the Icelandic statement “brúnn er litur” all express the same proposition.
According to Aristotle, each proposition that we use to express the facts about the world is either true, or it is false. Notice that because Aristotle takes truth to be a property of a proposition, truth is not appropriately applied to objects or events. So, for him, it is not appropriate to say that heptapods (the creatures in Arrival) are true aliens, but it is appropriate to consider whether the proposition “heptapods are aliens” is true. Different philosophers provide different theories concerning how we ought to assess the truth-value of propositions. We will examine some of those theories of truth in this chapter.
We might wonder whether any propositions are objectively true—that is, true independent of the perceptions, biases, feelings, and opinions of thinking beings. An objective truth would be a proposition that is true at all times, in all places, and for all rational beings. Many believe that mathematical truths, like “1 + 2 = 3,” are objective, as it seems that no matter who you are or where or when you live, it is true that 1 + 2 = 3. However, one might maintain that because math is a human invention, mathematical propositions cannot be objectively true. Perhaps we could have decided to use 6 (instead of 2) to name this many objects: * *. And in that case “1 + 2 = 3” would be false and “1 + 6 = 3” would be true, instead. But as we saw above, there could be different ways to express the same proposition. So, it is important to keep in mind that in the discussion of truth we are not so much interested in the symbols or the words used to express a proposition; instead we are interested in the proposition that those symbols and words are expressing. When assessing the truth of the proposition “1 + 2 = 3,” we focus not on the symbols (1, +, = and so on) but on the proposition that is being expressed by those symbols. In this case, the proposition indicates that when we put this many: * together with this many: * * we get this many: * * *. Indeed, we could use the word “Fred” to indicate this many objects: * *. But that would not change the fact that there are still just this many objects: * *. And because it is difficult to see how this many: * added to this many: * * could be anything other than this many: * * *, we can understand why so many philosophers believe that mathematical propositions are objectively true.
But even if there are some objectively true propositions, one might maintain that there are also subjective truths. A claim is subjectively true when it depends on what a person feels or perceives. Because two people can have different experiences of the same thing, and because beliefs and opinions can differ from person to person, it would seem that the same proposition could be true for one person but false for another. For example, Mary and Amy walk outside. Mary thinks that it is cold, and Amy thinks that it is hot. But then the proposition “it is cold outside” looks to be true for Mary, but false for Amy, in which case it would seem that the proposition must be subjectively—and not objectively—true. However, Aristotle would explain that the statement “it is cold outside” when uttered by Mary is not expressing the same proposition as it is when uttered by Amy. When Mary says, “It’s cold outside,” her statement expresses the proposition “it feels to me (Mary) that it is cold.” When Amy disagrees with Mary, Amy is not saying that Mary’s claim is false; instead, Amy is saying that a different proposition is true: “it feels to me (Amy) that it is hot.” Because Mary’s statement expresses what Mary is feeling and Amy’s statement is about what Amy is perceiving, the example is not of a single proposition that is true for one person and false for another; there are actually two different propositions being asserted, both of which can be true. Aristotle explains that, in general, whenever someone says, “It’s true for me that …,” what they are really saying is, “I believe that it is true.”
But how do we know whether a proposition is true or false? Before we examine the various theories of truth, let us first take a look at the film.
1.2 An Overview of the Movie
Arrival (2016). Directed by Denis VilleneuveStarring Amy Adams, Jeremy Renner, Forest Whitaker
Based on Ted Chiang’s short story entitled Story of Your Life, the film Arrival follows the experiences of Louise Banks, a linguist, and Ian Donnelly, a scientist, both of whom have been enlisted by U.S. Army officer, Colonel Weber, to figure out why a group of aliens—called heptapods—have arrived in 12 different places on Earth. The heptapods do not speak any human language, so in order determine what the purpose of the alien visit is, Louise must first figure out how to communicate with them. In accordance with the Sapir-Whorf hypothesis, as Louise becomes fluent in the alien language, she begins to see and think about the world in the way that the heptapods do. In particular, whereas humans experience time linearly and sequentially—one moment following another—heptapods experience time simultaneously—all moments all at once. Thus, as Louise becomes immersed in the heptapod language, she develops the ability to experience future events.
The film highlights the role that language plays when assessing truth. Sometimes a word in one language does not translate well to another, and sometimes a word might have two different interpretations. But if we are uncertain whether a certain heptapod term means “gift” or whether it means “weapon,” then a statement indicating that we ought to use it will mean one action if taken to mean “gift,” and a very different action when interpreted to mean “weapon.” How can we assess whether a statement is true or false if we are not certain what the words in the statement mean? And if there are different interpretations of the same term, how do we know which interpretation is correct? Or could it be the case that there is no one correct interpretation? As we will see in the next few sections, there are different answers to such questions depending on the theory of truth that is being considered.
1.3 The Correspondence Theory of Truth
In Section 1.1
, we saw that Aristotle maintains that a proposition is such that it is either true, or it is false (what is known as the law of excluded middle
). But what makes a true proposition true? According to Aristotle, a proposition is true when it corresponds to what is in fact the case, and a proposition is false when it does not correspond with what is in fact the case. For example, the proposition “a dog is an animal” is true because a dog that is in fact
an animal. The proposition “a dog is not an animal” is false because it does not align with the facts. So, Aristotle seems to posit a straight-forward theory of truth: a proposition is true if it matches up with reality or what is in fact the case.
(1872–1970) offers a theory of truth that is similar to Aristotle’s. Russell provides an explanation of his theory of truth in his book, The Problems of Philosophy
(1912). Selections from the chapter, “Truth and Falsehood,” are provided in Readings from Primary Sources (Reading 1a, 256). Russell focuses on beliefs
, rather than propositions. For him, a belief, like a proposition, proposes that an idea is either true or false. And on his account, “[A] belief is true when there is a corresponding fact, and is false when there is no corresponding fact.”2
In other words, a true belief matches up with what is in fact the case, and a false belief does not. So, according to both Aristotle and Russell, truth must include: (1) a proposition or belief and (2) reality or facts. When (1) corresponds
with (2), we have a true proposition or belief. This is the correspondence theory of truth
Russell explains that facts about the world are independent of thought, and thus there is a mind-independent reality—a world made up of objects that exists independently of what anyone or any group of people happens to think. Cognitive objectivism
is the position that combines the thesis that the world is mind-independent and the correspondence theory of truth. So, the cognitive objectivist holds that what makes a proposition or a belief true is its relationship to a fact about the world. And because the world is mind-independent, minds do not decide what is true and what is false. For the cognitive objectivist, then, there are only objective truths and no subjective truths. This means that if two people hold opposing views, they cannot both be asserting the truth. As Russell writes, “We know that on very many subjects different people hold different and incompatible opinions: hence some beliefs must be erroneous.” However, Russell explains, it is not always easy to know which beliefs are true and which are false: “Since erroneous beliefs are often
held just as strongly as true beliefs, it becomes a difficult question how they are to be distinguished from true beliefs.”3
Consider one of the crucial moments in the film: Louise asks the two heptapods—whom they have named Abbott and Costello—why they came to earth. The heptapods reply is “offer weapon” (MM 1:06:53). The Chinese General, Shang, interprets the phrase offer weapon as a threat to humanity; he believes that the heptapods want to turn humans against themselves in order to eliminate the human race. As a result of Shang’s interpretation, China declares war against the aliens and delivers an ultimatum to them: leave in 24 hours or face destruction. But Louise believes that the heptapods want to save humanity. She thinks that the aliens are offering a gift, not a weapon; the gift that is offered is the heptapod language and, with it, the ability to see the future. So, there are two opposing beliefs: Shang believes that the heptapods want to destroy humanity, and Louise believes that they do not. However, it soon becomes clear that Louise has a better understanding of the heptapod language, and it also becomes evident that her belief about the heptapods’ purpose on earth matches up with reality. By the end of the film, when Louise is able to read the heptapod writing, she learns that the heptapods need to help humanity so that three thousand years from now humans can help to save the heptapods. Thus, according to the correspondence theory, Louise’s belief—“the heptapods want to save humanity”—is true because it corresponds with the facts, and Shang’s belief—“the heptapods want to destroy humanity”—is false because it does not.
The above example presents another problem for the correspondence theory of truth. Although we do our best to use words to express what is going on in the world, there is an imperfect relationship between language and reality. Just try to get a group of words to perfectly convey a beautiful sunset; can anything that you say or write even come close to expressing it? In general, it seems that no group of words could ever come close to matching up exactly with actual objects. (In the next section, we will see that William James raises a similar objection against the correspondence theory). The correspondence theorist might respond by explaining that a true proposition only needs to correspond
with the facts and does not need to be an exact depiction of them. Moreover, as we explained in Section 1.1
of this chapter, it is not the words that matter, but the concept...