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All the ideas for 'Saundaranandakavya', 'The Upanishads' and 'Modal Logics and Philosophy'

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36 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
Pursue truth with the urgency of someone whose clothes are on fire [Ashvaghosha]
     Full Idea: As though your turban or your clothes were on fire, so with a sense of urgency should you apply your intellect to the comprehension of the truths.
     From: Ashvaghosha (Saundaranandakavya [c.50], XVI)
     A reaction: The best philosophers need no such urging. I retain a romantic view that we should be 'natural' in these things. See Plato's views in Idea 2153 and 1638. However, maybe I should be confronted with this quotation every morning when I awake.
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]
     Full Idea: Propositional logic can deal with negation, disjunction and conjunction of propositions, but predicate logic goes beyond it to deal with quantifiers, predicates and relations.
     From: Rod Girle (Modal Logics and Philosophy [2000], 1.1)
     A reaction: This is on the first page of an introduction to the next stage, which is to include modal notions like 'must' and 'possibly'.
There are three axiom schemas for propositional logic [Girle]
     Full Idea: The axioms of propositional logic are: A→(B→A); A→(B→C)→(A→B)→(A→C) ; and (¬A→¬B)→(B→A).
     From: Rod Girle (Modal Logics and Philosophy [2000], 6.5)
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
Proposition logic has definitions for its three operators: or, and, and identical [Girle]
     Full Idea: The operators of propositional logic are defined as follows: 'or' (v) is not-A implies B; 'and' (ampersand) is not A-implies-not-B; and 'identity' (three line equals) is A-implies-B and B-implies-A.
     From: Rod Girle (Modal Logics and Philosophy [2000], 6.5)
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle]
     Full Idea: An axiom system for a logic contains three elements: a set of axioms; a set of inference rules; and definitions for proofs and theorems. There are also definitions for the derivation of conclusions from sets of premises.
     From: Rod Girle (Modal Logics and Philosophy [2000], 6.5)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
There are seven modalities in S4, each with its negation [Girle]
     Full Idea: In S4 there are fourteen modalities: no-operator; necessarily; possibly; necessarily-possibly; possibly-necessarily; necessarily-possibly-necessarily; and possibly-necessarily-possibly (each with its negation).
     From: Rod Girle (Modal Logics and Philosophy [2000], 3.5)
     A reaction: This is said to be 'more complex' than S5, but also 'weaker'.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
◊p → □◊p is the hallmark of S5 [Girle]
     Full Idea: The critical formula that distinguishes S5 from all others is: ◊p → □◊p.
     From: Rod Girle (Modal Logics and Philosophy [2000], 3.3)
     A reaction: If it is possible that it is raining, then it is necessary that it is possible that it is raining. But if it is possible in this world, how can that possibility be necessary in all possible worlds?
S5 has just six modalities, and all strings can be reduced to those [Girle]
     Full Idea: In S5 there are six modalities: no-operator; necessarily; and possibly (and their negations). In any sequence of operators we may delete all but the last to gain an equivalent formula.
     From: Rod Girle (Modal Logics and Philosophy [2000], 3.5)
     A reaction: Such drastic simplification seems attractive. Is there really no difference, though, between 'necessarily-possibly', 'possibly-possibly' and just 'possibly'? Could p be contingently possible in this world, and necessarily possible in another?
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Possible worlds logics use true-in-a-world rather than true [Girle]
     Full Idea: In possible worlds logics a statement is true-in-a-world rather than just true.
     From: Rod Girle (Modal Logics and Philosophy [2000], 1.1)
     A reaction: This sounds relativist, but I don't think it is. It is the facts which change, not the concept of truth. So 'donkeys can talk' may be true in a world, but not in the actual one.
Modal logic has four basic modal negation equivalences [Girle]
     Full Idea: The four important logical equivalences in modal logic (the Modal Negation equivalences) are: ¬◊p↔□¬p, ◊¬p↔¬□p, □p↔¬◊¬p, and ◊p↔¬□¬p.
     From: Rod Girle (Modal Logics and Philosophy [2000], 1.2)
     A reaction: [Possibly is written as a diamond, necessarily a square] These are parallel to a set of equivalences between quantifiers in predicate logic. They are called the four 'modal negation (MN) equivalences'.
Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle]
     Full Idea: Modal logics were, for a long time, studied in terms of axiom systems. The advent of possible worlds semantics made it possible to study them in a semantic way as well.
     From: Rod Girle (Modal Logics and Philosophy [2000], 6.5)
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle]
     Full Idea: Necessary implication is often called 'strict implication'. The sort of strict implication found in valid arguments, where the conjunction of the premises necessarily implies the conclusion, is often called 'entailment'.
     From: Rod Girle (Modal Logics and Philosophy [2000], 1.2)
     A reaction: These are basic concept for all logic.
5. Theory of Logic / H. Proof Systems / 5. Tableau Proof
If an argument is invalid, a truth tree will indicate a counter-example [Girle]
     Full Idea: The truth trees method for establishing the validity of arguments and formulas is easy to use, and has the advantage that if an argument or formula is not valid, then a counter-example can be retrieved from the tree.
     From: Rod Girle (Modal Logics and Philosophy [2000], 1.4)
10. Modality / A. Necessity / 3. Types of Necessity
Analytic truths are divided into logically and conceptually necessary [Girle]
     Full Idea: It has been customary to see analytic truths as dividing into the logically necessary and the conceptually necessary.
     From: Rod Girle (Modal Logics and Philosophy [2000], 7.3)
     A reaction: I suspect that this neglected distinction is important in discussions of Quine's elimination of the analytic/synthetic distinction. Was Quine too influenced by what is logically necessary, which might shift with a change of axioms?
10. Modality / B. Possibility / 1. Possibility
Possibilities can be logical, theoretical, physical, economic or human [Girle]
     Full Idea: Qualified modalities seem to form a hierarchy, if we say that 'the possibility that there might be no hunger' is possible logically, theoretically, physically, economically, and humanly.
     From: Rod Girle (Modal Logics and Philosophy [2000], 7.3)
     A reaction: Girle also mentions conceptual possibility. I take 'physically' to be the same as 'naturally'. I would take 'metaphysically' possible to equate to 'theoretically' rather than 'logically'. Almost anything might be logically possible, with bizarre logic.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle]
     Full Idea: When one world generates another then it has 'access' to the world it generated. The accessibility relation between worlds is very important in possible worlds semantics.
     From: Rod Girle (Modal Logics and Philosophy [2000], 3.2)
     A reaction: This invites the obvious question what is meant by 'generates'.
16. Persons / A. Concept of a Person / 3. Persons as Reasoners
Self is the rider, intellect the charioteer, mind the reins, and body the chariot [Anon (Upan)]
     Full Idea: Know that the Self (Atman) is the rider, and the body the chariot; that the intellect is the charioteer, and the mind the reins.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: This strikes me as exactly right. Even my intellectual powers are servants of the self. This suggests the view of the mind as a tool, which does not seem to occur in modern discussions.
16. Persons / C. Self-Awareness / 2. Knowing the Self
We have an apparent and a true self; only the second one exists, and we must seek to know it [Anon (Upan)]
     Full Idea: There are two selves, the apparent self, and the real Self. Of these it is the real Self (Atman), and he alone, who must be felt as truly existing. To the man who has felt him as truly existing he reveals his innermost nature.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: A central Hindu doctrine against which Buddhism rebelled, by denying the self altogether. I prefer the Hindu view. A desire to abandon the self just seems to be a desire for death. Knowledge of our essential self is more interesting. But see Idea 2932!
18. Thought / D. Concepts / 5. Concepts and Language / a. Concepts and language
Without speech we cannot know right/wrong, true/false, good/bad, or pleasant/unpleasant [Anon (Upan)]
     Full Idea: If there were no speech, neither right nor wrong would be known, neither the true nor the false, neither the good nor the bad, neither the pleasant nor the unpleasant.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Chandogya')
     A reaction: This could stand as the epigraph for the whole of modern philosophy of language. However, the text goes on to say that mind is higher than speech. The test question is the mental capabilities of animals. Do they 'know' pleasure, or truth?
22. Metaethics / C. The Good / 3. Pleasure / c. Value of pleasure
The wise prefer good to pleasure; the foolish are drawn to pleasure by desire [Anon (Upan)]
     Full Idea: The wise prefer the good to the pleasant; the foolish, driven by fleshly desires, prefer the pleasant ot the good.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: If you consider appropriate diet, this is too obvious to be worth saying. The complication is that it is doubtful whether a life without pleasure is wholly good, and even the pleasure of food is not bad. Of two good foods, prefer the pleasant one.
25. Social Practice / E. Policies / 5. Education / c. Teaching
Let your teacher be a god to you [Anon (Upan)]
     Full Idea: Let your teacher be a god to you.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Taittiriya')
     A reaction: Yes indeed. The problem in the west is that we are committed to encouraging a critical and questioning attitude. A high value for knowledge must precede a high value for a teacher.
26. Natural Theory / B. Natural Kinds / 2. Defining Kinds
By knowing one piece of clay or gold, you know all of clay or gold [Anon (Upan)]
     Full Idea: By knowing one lump of clay, all things made of clay are known; by knowing a nugget of gold, all things made of gold are known.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Chandogya')
     A reaction: I can't think of a better basic definition of a natural kind. There is an inductive assumption, of course, which hits trouble when you meet fool's gold, or two different sorts of jade. But the concept of a natural kind is no more than this.
27. Natural Reality / E. Cosmology / 2. Eternal Universe
Originally there must have been just Existence, which could not come from non-existence [Anon (Upan)]
     Full Idea: In the beginning there was Existence, One only, without a second. Some say that in the beginning there was non-existence only, and that out of that the universe was born. But how could such a thing be? How could existence be born of non-existence?
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Chandogya')
     A reaction: A very rare instance of an argument in the Upanishads, arising out of a disagreement. The monotheistic religions have preferred to make God the eternal element, presumably because that raises his status, but is also explains the start as a decision.
28. God / A. Divine Nature / 1. God
Brahma, supreme god and protector of the universe, arose from the ocean of existence [Anon (Upan)]
     Full Idea: Out of the infinite ocean of existence arose Brahma, first-born and foremost among the gods. From him sprang the universe, and he became its protector.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Mundaka')
     A reaction: Brahma does not have eternal (or necessary) existence. Could Brahma cease to exist? I suppose we cannot ask what caused the appearance of Brahma? Is it part of a plan, or just luck, or some sort of necessity?
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
Brahman is the Uncaused Cause [Anon (Upan)]
     Full Idea: Brahman is the Uncaused Cause.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: This precedes Aquinas (Idea 1430) by over two thousand years. The theological trick is to admit one Uncaused Cause, but somehow exclude further instances, such as my bicycle getting a puncture. Does this undermine the Principle of Sufficient Reason?
28. God / C. Attitudes to God / 2. Pantheism
Earth, food, fire, sun are all forms of Brahman [Anon (Upan)]
     Full Idea: Earth, food, fire, sun - all these that you worship - are forms of Brahman.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Chandogya')
     A reaction: In 'Taittiriya' food is named as the "chief of all things". Pantheism seems to arise from a desire that one's god should have every conceivable good, so in addition to power and knowledge, your god must keep you warm and healthy.
29. Religion / A. Polytheistic Religion / 3. Hinduism
The gods are not worshipped for their own sake, but for the sake of the Self [Anon (Upan)]
     Full Idea: It is not for the sake of the gods, my beloved, that the gods are worshipped, but for the sake of the Self (Atman).
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Brihadaranyaka')
     A reaction: There is an uneasy selfish streak in all religions, which conflicts with their exhorations to altruism, and to the love of the gods. It also occurs in the exhortation of Socrates to be virtuous. 'Pure' altruism seems only to arise in the 18th century.
A man with desires is continually reborn, until his desires are stilled [Anon (Upan)]
     Full Idea: A man acts according to desires; after death he reaps the harvest of his deeds, and returns again to the world of action. Thus he who has desires continues subject to rebirth, but he in who desire is stilled suffers no rebirth.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Brihadaranyaka')
     A reaction: I greatly prefer the Stoic idea (Idea 3066) that we should live according to nature, to this perverse longing to completely destroy our own nature and become something we are not. Play the cards you are dealt, which include desires.
Damayata - be self-controlled! Datta - be charitable! Dayadhwam - be compassionate! [Anon (Upan)]
     Full Idea: The storm-clouds thunder: Da! Da! Da! Damayata - be self-controlled! Datta - be charitable! Dayadhwam - be compassionate!
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Brihadaranyaka')
     A reaction: Compassion seems to imply charity, so it comes down to 'Be self-controlled and compassionate'. Only the wildest romantic could be against self-control. Only Nietzsche could be against compassion (Idea 4425).
Those ignorant of Atman return as animals or plants, according to their merits [Anon (Upan)]
     Full Idea: Of those ignorant of the Self (Atman), some enter into beings possessed of wombs, others enter into plants - according to their deeds and the growth of their intelligence.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: "I sigh and sigh, and wish I were a tree" wrote George Herbert. You probably need the snobbery of the Indian caste system to appreciate the horrors of low rebirth. I quite fancy being a dolphin, but a tulip would be all right.
29. Religion / C. Spiritual Disciplines / 3. Buddhism
The Eightfold Path concerns morality, wisdom, and tranquillity [Ashvaghosha]
     Full Idea: The Eightfold Path has three steps concerning morality - right speech, right bodily action, and right livelihood; three of wisdom - right views, right intentions, and right effort; and two of tranquillity - right mindfulness and right concentration.
     From: Ashvaghosha (Saundaranandakavya [c.50], XVI)
     A reaction: Most of this translates quite comfortably into the aspirations of western philosophy. For example, 'right effort' sounds like Kant's claim that only a good will is truly good (Idea 3710). The Buddhist division is interesting for action theory.
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Charity and ritual observance distract from the highest good of religion [Anon (Upan)]
     Full Idea: Considering religion to be observance of rituals and performance of acts of charity, the deluded remain ignorant of the highest good.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Mundaka')
     A reaction: An important reminder. In all the great religious texts the exhortation to love and charity is a minor aspect. The point is to live on a spiritual plain, attempting to relate the world of God/the gods. Daily life is either secondary or irrelevant.
29. Religion / D. Religious Issues / 1. Religious Commitment / e. Fideism
Do not seek to know Brahman by arguments, for arguments are idle and vain [Anon (Upan)]
     Full Idea: Do not seek to know Brahman by arguments, for arguments are idle and vain.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Brihadaranyaka')
     A reaction: In the end all the religions seem to gravitate towards fideism and away from reasoned argument. The Catholic Church may be the last bastion of rational theology. Islam (10th cent), Protestantism (16th) and Judaism (17th) all rejected philosophy.
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
The immortal in us is the part that never sleeps, and shapes our dreams [Anon (Upan)]
     Full Idea: That which is awake in us even while we sleep, shaping in dream the objects of our desire - that indeed is pure, that is Brahman, and that verily is called the Immortal.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
     A reaction: That is a more helpful view of what the soul might be than anything found in Christian theology. It makes it the essence of the everyday Self. It is left with the difficulty of lacking individuality, and being of limited interest to my wider Self.
The immortal Self and the sad individual self are like two golden birds perched on one tree [Anon (Upan)]
     Full Idea: Like two birds of golden plumage, the individual self and the immortal Self perch on the branches of the same tree. The individual self, deluded by forgetfulness of his identity with the divine self, bewildered by his ego, grieves and is sad.
     From: Anon (Upan) (The Upanishads [c.950 BCE], 'Mundaka')
     A reaction: Hinduism gives a much clearer and bolder picture of the soul than Christianity does. I don't see much consolation in the immortality of the wonderful Self, if my individual self is doomed to misery and extinction. Which one is me?
29. Religion / D. Religious Issues / 2. Immortality / d. Heaven
At the end of a saint, he is not located in space, but just ceases to be disturbed [Ashvaghosha]
     Full Idea: When an accomplished saint comes to the end, he does not go anywhere down in the earth or up in the sky, nor into any of the directions of space, but because his defilements have become extinct he simply ceases to be disturbed.
     From: Ashvaghosha (Saundaranandakavya [c.50], XVI)
     A reaction: To 'cease to be disturbed' is the most attractive account of heaven I have encountered. It all sounds a bit dull though. I wonder, as usual, how they know all this stuff.