Online research in philosophy

The received definition of knowledge (as true, evident belief) has recently been questioned by Edmund Gettier with an example whose principle is as follows. A proposition, p, is both evident to and accepted by someone S, who sees that its truth entails (would entail) (that either p is true or q is true). This last is thereby made evident to him, and he accepts it, but it happens to be true only because q is true, since p is in fact false. Hence, inasmuch as he has no evidence for the proposition q, S can hardly be said to know (that either p is true or q is true). Here then is a formula for true, evident beliefs that are not cases of knowledge. I discuss the possibility of adding a fourth condition to this triad.

Many people face a problem about potentiality: their moral beliefs appear to dictate inconsistent views about the significance of the potentiality to become a healthy adult. Briefly, the problem arises as follows. Consider the following two claims. First, both human babies and cats have moral status, but harms to babies matter more, morally, than similar harms to cats. Second, early human embryos lack moral status. It appears that the first claim can only be true if human babies have more moral status than cats. Among the properties that determine moral status, human babies have no properties other than their potentiality that could explain their having more moral status than cats. So human babies’ potentiality to become adult persons must explain their having more moral status than cats. But then potentiality must raise moral status generally. So early human embryos must have some moral status. It appears that the view that must underlie the first claim implies that the second claim is false.

The term fuzzy logic is used in this paper to describe an imprecise logical system, FL, in which the truth-values are fuzzy subsets of the unit interval with linguistic labels such as true, false, not true, very true, quite true, not very true and not very false, etc. The truth-value set, , of FL is assumed to be generated by a context-free grammar, with a semantic rule providing a means of computing the meaning of each linguistic truth-value in as a fuzzy subset of [0, 1].Since is not closed under the operations of negation, conjunction, disjunction and implication, the result of an operation on truth-values in requires, in general, a linguistic approximation by a truth-value in . As a consequence, the truth tables and the rules of inference in fuzzy logic are (i) inexact and (ii) dependent on the meaning associated with the primary truth-value true as well as the modifiers very, quite, more or less, etc.

Summary According to the Redundance Theory of Truth, the utterance it is true thatp means nothing more than simply ‘p’. So the utterance is true would be meaningless, redundant. The Redundance Theory overlooks that the the predicate true can be used in two applications: (a) as anassertion of the justness of a proposition, (b) as ajudgement of the justness of a proposition. (The word justness in this context means the correspondance of a proposition with reality according to the Theory of Correspondence.) The explicitassertion of the justness is indeed superfluous as it is implicitly included in the proposition. Thejudgement of the justness of a proposition, however, cannot be included in the proposition analytically. In this way, the utterance it is true thatp does not only mean ‘p’ but the assertion that is implicitly included in the proposition ‘p’ (= ‘p’ is true ) is true . Analogous: the utterance it is false that ‘p’ means the assertion that is implicitly included in the proposition ‘p’ (= ‘p’ is true ) is false . A judgement like this exceeds the content of a proposition and so cannot be redundant. Although in some context the words true and false may be used in their application an an assertion because of stylistic reasons, they are relevant for any theory of truth only in their application as a judgment, which cannot be contested by the reproach of redundance. The claim of the Redundance Theory that the concept of truth is meaningless and superfluous must be refused.

Something is called true because it conforms to some measure. Since what measures is logically prior to what it measures, the latter is always secondarily speaking true. Further, what is secondarily speaking true pictures its measure. In all there are six types of such picturing. Since “true” is inherently referential and the latter is the mark of mind, truth is properly speaking mind-dependent. Besides, truth has the same status as falsity, and falsity is mind-dependent. That implies that the measures in truth are mind-dependent. That mind is either human or divine. All mind-independent things are improperly speaking true. They are called true only because they bear some relation to what is strictly speaking true. But not all that is secondarily speaking true is improperly speaking true. Judgments are secondarily speaking true since they are measured by facts but are nonetheless properly speaking true. A nominalist alternative to this assay is traced to Aristotle. It is too narrow to catch all types of truth. A conceptualist analysis implicates its defenders in a dilemma in which what they say is either false or contradictory.

Bob Hale in Hale 1995b posed a dilemma for modal fictionalism (more specifically, Rosen's version of modal fictionalism). A modal fictionalist who maintains the version outlined in Rosen 1990 believes that the fiction of possible worlds (PW, to use Rosen and Hale's abbreviation) is not literally true. The question arises, however, about its modal status. Is it necessarily false, or contingently false? In either case, Hale argues, the modal fictionalist is in trouble. Should the modal fictionalist claim that the story of possible worlds is necessarily false, then the modal fictionalist cannot gloss their "according to the fiction of possible worlds ... ." prefix as "were the fiction of possible worlds true, then ... would be true". This is because, according to Hale, conditional claims with antecedents which are necessarily false are automatically true, so it follows that if the fiction of possible worlds is taken to be necessarily false, all conditionals of the form "were the fiction of possible worlds true then ..." are true, and not merely the ones that the modal fictionalist wishes to endorse. If the modal fiction is to be useful, not everything should be true according to it: examples of claims that had better not be true according to it include the claim that 2+2=7, or the claim that there are no possible worlds. On the other hand, if the fiction of possible worlds (PW) is only contingently false, Hale claims this also lands the Rosen's fictionalism in unacceptable trouble, though it is not so clear why (see below). Let me discuss these horns in turn.

We describe the earliest occurrences of the Liar Paradox in the Arabic tradition. e early Mutakallimūn claim the Liar Sentence is both true and false; they also associate the Liar with problems concerning plural subjects, which is somewhat puzzling. Abharī (1200-1265) ascribes an unsatisfiable truth condition to the Liar Sentence—as he puts it, its being true is the conjunction of its being true and false—and so concludes that the sentence is not true. Tūsī (1201-1274) argues that self-referential sentences, like the Liar, are not truth-apt, and defends this claim by appealing to a correspondence theory of truth. Translations of the texts are provided as an appendix.

The claim that truth is mind dependent has some initial plausibility only if truth bearers are taken to be mind dependent entities such as beliefs or statements. Even on that assumption, however, the claim is not uncontroversial. If it is spelled out as the thesis that “in a world devoid of mind nothing would be true”, then everything depends on how the phrase ‘true in world w’ is interpreted. If ‘A is true in w’ is interpreted as ‘A is true of w’ (i.e. ‘w satisfies A’s truth conditions’, the claim need not be true. If on the other hand it is interpreted as ‘A is true of w and exists in w’ then the claim is trivially true, though devoid of any antirealistic efficacy. Philosophers like Heidegger and Rorty, who hold that truth is mind dependent but reality is not, must regard such principles as “A if and only if it is true that A” as only contingently true, which may be a good reason to reject the mind dependence of truth anyway.

Logic begins but does not end with the study of truth and falsity. Within truth there are the modes of truth, ways of being true: necessary truth and contingent truth. When a proposition is true, we may ask whether it could have been false. If so, then it is contingently true. If not, then it is necessarily true; it must be true; it could not have been false. Falsity has modes as well: a false proposition that could not have been true is impossible or necessarily false; one that could have been true is merely contingently false. The proposition that some humans are over seven feet tall is contingently true; the proposition that all humans over seven feet tall are over six feet tall is necessarily true; the proposition that some humans are over seven feet tall and under six feet tall is impossible, and the proposition that some humans are over nine feet tall is contingently false. Of these four modes of truth, let us focus on necessity, plus a fth: possibility. A proposition is possible if it is or could have been true; hence propositions that are either necessarily true, contingently true, or contingently false are possible. Notions that are similar to the modes of truth in being concerned with what might have been are called modal. Dispositions are modal notions, for example the disposition of fragility. Relatedly, there are counterfactual conditionals, for example “if this glass were dropped, it would break.” And the notion of supervenience is modal.1 But let us focus here on necessity and possibility. Modal words are notoriously ambiguous (or at least context-sensitive2). I may reply to an invitation to give a talk in England by saying “I can’t come; I have to give a talk in California the day before”. This use of “can’t” is perfectly appropriate. But it would be equally appropriate for me to say that I could cancel my talk in California (although that would be rude) and give the talk in England instead. What I cannot do is give both talks. But wait: it also seems appropriate to say, in another context, that given contemporary transportation..

Logic begins but does not end with the study of truth and falsity. Within truth there are the modes of truth, ways of being true: necessary truth and contingent truth. When a proposition is true, we may ask whether it could have been false. If so, then it is contingently true. If not, then it is necessarily true; it must be true; it could not have been false. Falsity has modes as well: a false proposition that could not have been true is impossible or necessarily false; one that could have been true is merely contingently false. The proposition that some humans are over seven feet tall is contingently true; the proposition that all humans over seven feet tall are over six feet tall is necessarily true; the proposition that some humans are over seven feet tall and under six feet tall is impossible, and the proposition that some humans are over nine feet tall is contingently false. Of these four modes of truth, let us focus on necessity, plus a fifth: possibility. A proposition is possible if it is or could have been true; hence propositions that are either necessarily true, contingently true, or contingently false are possible. Notions that are similar to the modes of truth in being concerned with what might have been are called modal. Dispositions are modal notions, for example the disposition of fragility. Relatedly, there are counterfactual conditionals, for example “if this glass were dropped, it would break.” And the notion of supervenience is modal.1 But let us focus here on necessity and possibility. Modal words are notoriously ambiguous (or at least context-sensitive2). I may reply to an invitation to give a talk in England by saying “I can’t come; I have to give a talk in California the day before”. This use of “can’t” is perfectly appropriate. But it would be equally appropriate for me to say that I could cancel my talk in California (although that would be rude) and give the talk in England instead. What I cannot do is give both talks..