Combining Texts

All the ideas for 'On the Philosophy of Logic', 'Truth' and 'Essence and Accident'

unexpand these ideas     |    start again     |     specify just one area for these texts


20 ideas

2. Reason / A. Nature of Reason / 1. On Reason
We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher]
     Full Idea: A state of 'reflective equilibrium' is when our theory and our intuitions become completely aligned
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.IV)
     A reaction: [Rawls made this concept famous] This is a helpful concept in trying to spell out the ideal which is the dream of believers in 'pure reason' - that there is a goal in which everything comes right. The problem is when people have different intuitions!
3. Truth / C. Correspondence Truth / 2. Correspondence to Facts
The fact which is stated by a true sentence is not something in the world [Strawson,P]
     Full Idea: The fact which is stated by a true sentence is not something in the world.
     From: Peter F. Strawson (Truth [1950], §2)
     A reaction: Everything is in the world. This may just be a quibble over how we should use the word 'fact'. At some point the substance of what is stated in a sentence must eventually be out there, or we would never act on what we say.
Facts aren't exactly true statements, but they are what those statements say [Strawson,P]
     Full Idea: Facts are what statements (when true) state; they are not what statements are about. ..But it would be wrong to identify 'fact' and 'true statement' for these expressions have different roles in our language.
     From: Peter F. Strawson (Truth [1950], §2)
     A reaction: Personally I like to reserve the word 'facts' for what is out there, independent of any human thought or speech. As a realist, I believe that the facts are quite independent of our attempts to understand the facts. True statements attempt to state facts.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
The statement that it is raining perfectly fits the fact that it is raining [Strawson,P]
     Full Idea: What could fit more perfectly the fact that it is raining than the statement that it is raining?
     From: Peter F. Strawson (Truth [1950], §2)
3. Truth / F. Semantic Truth / 2. Semantic Truth
The word 'true' always refers to a possible statement [Strawson,P]
     Full Idea: It is of prime importance to distinguish the fact that the use of 'true' always glances backwards or forwards to the actual or envisaged making of a statement by someone.
     From: Peter F. Strawson (Truth [1950], §1)
     A reaction: 'The truth of this matter will never be known'. Strawson is largely right, but it is crazy for any philosopher to use the word 'always' if they can possibly avoid it.
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher]
     Full Idea: In three-valued logic (L3), neither the law of excluded middle (p or not-p), nor the law of non-contradiction (not(p and not-p)) will be tautologies. If p has the value 'indeterminate' then so will not-p.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.I)
     A reaction: I quite accept that the world is full of indeterminate propositions, and that excluded middle and non-contradiction can sometimes be uncertain, but I am reluctant to accept that what is being offered here should be called 'logic'.
4. Formal Logic / E. Nonclassical Logics / 4. Fuzzy Logic
Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher]
     Full Idea: In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II)
     A reaction: The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher]
     Full Idea: For simplicity, we can say that 'classical logic' amounts to the truth of four sentences: 1) either p or not-p; 2) it is not the case that both p and not-p; 3) from p and not-p, infer q; 4) from p or q and not-p, infer q.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.I)
     A reaction: [She says there are many ways of specifying classical logic] Intuition suggests that 2 and 4 are rather hard to dispute, while 1 is ignoring some grey areas, and 3 is totally ridiculous. There is, of course, plenty of support for 3!
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher]
     Full Idea: Even if one is inclined to be a realist about everything, it is hard to see why our logic should be the determiner. Logic is supposed to formalize how we ought to reason, but whether or not we should be realists is a matter of philosophy, not logic.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 09.I)
     A reaction: Nice to hear a logician saying this. I do not see why talk in terms of an object is a commitment to its existence. We can discuss the philosopher's stone, or Arthur's sword, or the Loch Ness monster, or gravitinos, with degrees of commitment.
7. Existence / D. Theories of Reality / 10. Vagueness / g. Degrees of vagueness
We could make our intuitions about heaps precise with a million-valued logic [Fisher]
     Full Idea: We could construct a 1,000,000-valued logic that would allow our intuitions concerning a heap to vary exactly with the amount of sand in the heap.
     From: Jennifer Fisher (On the Philosophy of Logic [2008])
     A reaction: Presumably only an infinite number of grains of sand would then produce a true heap, and even one grain would count as a bit of a heap, which must both be wrong, so I can't see this helping much.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / b. Dispositions and powers
The real essence of a thing is its powers, or 'dispositional properties' [Copi]
     Full Idea: With respect to scientific usage, we can say that the real essence of a thing will consist very largely of powers or, in modern terms, dispositional properties.
     From: Irving M. Copi (Essence and Accident [1954], p.718)
     A reaction: Once again, Copi is a hero. I personally love the word 'powers' in metaphysics (and dislike the word 'properties', which is lost in a fog of confusion). See Molnar on 'powers' and Mumford on 'dispositions'.
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vagueness can involve components (like baldness), or not (like boredom) [Fisher]
     Full Idea: Vague terms come in at least two different kinds: those whose constituent parts come in discrete packets (bald, rich, red) and those that don't (beauty, boredom, niceness).
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II)
     A reaction: The first group seem to be features of the external world, and the second all occur in the mind. Baldness may be vague, but presumably hairs are (on the whole) not. Nature doesn't care whether someone is actually 'bald' or not.
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Essential properties are the 'deepest' ones which explain the others [Copi, by Rami]
     Full Idea: The 'explanatory characterization' says that the essential properties of an object are the object's deepest explanatory properties, which explain the other properties of the object - and which Copi claims is mind-independent.
     From: report of Irving M. Copi (Essence and Accident [1954]) by Adolph Rami - Essential vs Accidental Properties §2
     A reaction: It is, of course, normal to see a good explanation as being dependent on the interests of the audience. Perhaps this account should be in terms of causal powers. See Shoemaker on properties.
9. Objects / D. Essence of Objects / 13. Nominal Essence
In modern science, nominal essence is intended to be real essence [Copi]
     Full Idea: In the sphere of scientific enquiry the distinction between real and nominal essence tends to disappear; the scientist's classification of things is intended to be in terms of their real essences.
     From: Irving M. Copi (Essence and Accident [1954], p.716)
     A reaction: Thus we have disputes over what is the 'real' classification of natural kinds such as animals. There is not much point in a classification system that does not at least reflect some aspects of reality.
9. Objects / E. Objects over Time / 11. End of an Object
Within the four types of change, essential attributes are those whose loss means destruction [Copi]
     Full Idea: If we can distinguish the different kinds of change (alteration, locomotion, growth, diminution), then we can say that a given attribute is essential to an object if its loss would result in the destruction of that object.
     From: Irving M. Copi (Essence and Accident [1954], p.707-8)
     A reaction: As Copi is aware, this is a necessary condition for a property for essence, but not sufficient. If an attribute were necessary but non-essential, its loss would also be destruction. We say the essential attributes must also have some explanatory role.
10. Modality / B. Possibility / 1. Possibility
We can't explain 'possibility' in terms of 'possible' worlds [Fisher]
     Full Idea: Explaining 'it is possible that p' by saying p is true in at least one possible world doesn't get me very far. If I don't understand what possibility is, then appealing to possible worlds is not going to do me much good.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 06.III)
     A reaction: This seems so blatant that I assume friends of possible worlds will have addressed the problem. Note that you will also need to understand 'possible' to define necessity as 'true in all possible worlds'. Necessarily-p is not-possibly-not-p.
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher]
     Full Idea: If all truths are implied by a falsehood, then 'if there are no trees in the park then there is no shade' and 'if there are no trees in the park there is plenty of shade' both come out as true. Intuitively, though, the second one is false.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.I)
     A reaction: The rule that a falsehood implies all truths must be the weakest idea in classical logic, if it actually implies a contradiction. This means we must take an interest in relevance logics.
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher]
     Full Idea: A good account of relevance logic suggests that a conditional will be true when the flow of information is such that a conditional is the device that helps information to flow from the antecedent to the consequent.
     From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.III)
     A reaction: Hm. 'If you are going out, you'll need an umbrella'. This passes on information about 'out', but also brings in new information. 'If you are going out, I'm leaving you'. What flows is an interpretation of the antecedent. Tricky.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Modern science seeks essences, and is getting closer to them [Copi]
     Full Idea: Modern science seeks to know the real essences of things, and its increasing successes seem to be bringing it progressively nearer to that goal.
     From: Irving M. Copi (Essence and Accident [1954], p.715)
     A reaction: This is from a notable pioneering paper, which outlined scientific essentialism even before Marcus and Kripke began to offer a modern account of essence to give it backing. Compare Popper, who thinks essences are will-o-the-wisps.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / d. Knowing essences
Real essences are scientifically knowable, but so are non-essential properties [Copi]
     Full Idea: Contrary to Locke, I should hold that real essences are in principle knowable, and contrary to Aristotle, I should hold that non-essential or accidental properties can also be objects of scientific knowledge.
     From: Irving M. Copi (Essence and Accident [1954], p.717)
     A reaction: Copi has just become my hero. Aristotle's account of definition is on the brink of allowing fine-tuned essences, but he thinks universal understanding blocks knowledge of individuals. But cross-referencing of universals pinpoints individuals.