PHL280: Truth and Reality
Week 1: Introduction to Truth

    Truth

  1. There seems to be such a thing as truth – a property that some things have (the things that are true), and other things lack (the things that are not true):
  2. Truth thus seems to be a property, like the property of being red, or the property of being a chair.
  3. Our main question

  4. We will mainly be concerned with the question: What is truth? Or: What is the nature of truth?
  5. Since it is not really clear what this question is asking, we will do what many philosophers do and ask the following related question instead: What does it take for something to be true? Or: Under what conditions is something true?
  6. What we are looking for in answer to this question is a true claim of the following form:

    Necessarily: for all x: x is true if and only if ...

  7. Here is an answer of the right form (whether or not it is true is something that we will be considering in detail later):

    Necessarily: for all x: x is true iff x corresponds to the facts

  8. Why include the word ‘Necessarily’? Why not just look for an answer of the following form?

    For all x: x is true iff ...

  9. Because even if we come up with a true claim of this second form it might not tell us much about the nature of truth. To see why, consider the following claim:

    For all x: x has a heart iff x has a kidney

    This is true, but it doesn't tell us much about the nature of having a heart - about what it is to have a heart. The following claim might tell us more about the nature of having a heart, but unfortunately it is arguably false:

    Necessarily: for all x: x has a heart iff x has a kidney

  10. Keep in mind, though, that even if we come up with a true claim of the form in the box above, it might not tell us much about the nature of truth either. For here is a true claim that does not tell us much about the nature of being trilateral:

    Necessarily: for all x: x is trilateral iff x has three angles.

  11. Even so, we will be happy if we can come up with a true claim of the form in the box above (this turns out to be difficult).
  12. Note that our main question is about truth, not about the English word 'truth', and not about our concept TRUTH. These are three distinct things: we use the word 'truth' to refer to truth, employing our concept TRUTH in the process. Perhaps when trying to figure out the nature of truth we will need to think about the word 'truth' and/or the concept TRUTH, but our ultimate interest is in truth itself.
  13. Why the interest in truth?

  14. We will be spending the entire semester thinking about truth. Why?
  15. First, it is something that we care about in our daily lives, so it would be nice to know a little more about what it is that we care about:
  16. Second, many philosophical theories use truth to explain other things, so it would be nice to know a little more about what it is that these theories use:
  17. Third, it has proven very tricky to work out the nature of truth, and trying to do so raises many interesting philosophical issues.
  18. Why think we can do it?

  19. Why think that we can figure out the nature of truth, given that we are philosophers and do everything from the armchair? After all, we wouldn’t expect to be able to figure out the nature of electrons from the armchair - that takes interaction with the world.
  20. Well, we seem to have the ability to sort things that are true from things that are not true, which suggests that we already know what it takes for something to be true, even if we have that knowledge only implicitly. Perhaps what we can do from the armchair is make that knowledge explicit.
  21. Perhaps this is too bold. Perhaps what we already have is only an implicit theory (rather than knowledge) of truth, and what we can do from the armchair is make that theory explicit. Perhaps we will discover that the theory is false, or even inconsistent (the liar paradox will suggest this). That would still be an interesting discovery.
  22. Note, also, that each of us has done a lot of interacting with the world, and comes to the armchair already equipped with a lot of knowledge/theory.
  23. Falsity

  24. There also seems to be such a thing as falsity - a property that some things have (the things that are false), and other things lack (the things that are not false):
  25. Note that some things are neither true nor false - Sydney, for example, is neither true nor false. So just because something is not true that doesn’t mean that it need be false.
  26. Sydney is neither true nor false because it is not the kind of thing that can be true or false. It is not truth apt; it is not a bearer of truth. Beliefs and claims, on the other hand, are the kinds of things that can be true or false. They are truth apt; they are bearers of truth.
  27. Because some things are not truth-apt, the following law, the law of bivalence, is not true in general:

    Necessarily: for all x: either x is true or x is false

  28. Perhaps, though, it is true when restricted to things that are truth-apt. Perhaps the following is true:

    Necessarily: for all beliefs x: either x is true or x is false

    This is controversial. Some think that beliefs about the future are neither true nor false, some think that beliefs about borderline cases are neither true nor false, some think that moral beliefs are neither true nor false. More about this later.
  29. Primary bearers of truth

  30. There seem to be various kinds of bearers of truth:
  31. But perhaps we can limit our attention to things of just one kind.
  32. First, notice that when we call things in the second list ‘true’ we are arguably using ‘true’ with a special meaning – something like ‘real’, or ‘genuine’. We shall set aside this use of ‘true’ and ignore everything on the second list.
  33. Next, notice that ‘belief’ in the first list can be used to refer to two different things. It can be used to refer to the act of believing, or to the object of this act (we might say that 'belief' is act-object ambiguous).

    Suppose that you and I both believe that grass is green. In the first sense of ‘belief’ there are two different beliefs here – two different acts of believing, one by you, one by me. But in the second sense of 'belief' there is just one belief - the common object of our acts of believing, the thing that we both believe, the proposition that grass is green.

    Whether or not a belief act is true depends on whether or not its object is true. So we can fairly easily explain the conditions under which a belief act is true: it is true just in case its object (a certain proposition) is true.

  34. Next, notice that we can say the same kind of thing for everything else on the first list. So whether or not a certain act of assuming is true (for example), depends on whether or not the object of the assuming (a certain proposition) is true. Thus, among all the bearers of truth we can take it that propositions are the primary bearers of truth (and all the others are only secondary bearers).
  35. Then all we have left to explain is what it takes for a proposition to be true. We will focus on propositions throughout this course, and on what it takes for them to be true.
  36. Note, though, that not everyone agrees. Some take the primary bearers of truth to be sentences of public language, others take them to be sentences of a language of thought.
  37. What are propositions? That's a tricky question, and there is lots of disagreement. For now we will take it that there are such things (that's controversial too), that they are the objects of beliefs, assumptions, assertions, etc., and that they are the primary bearers of truth. We will consider propositions in more detail as the course goes on.

Exercise

Read Soames, Chapter 1. Explain the difference between a sentence (sentence type), an utterance (sentence token), and a proposition. What reason(s) does Soames give for thinking that propositions and not sentences or utterances are the primary bearers of truth? (This comes right at the end of the chapter.)