33 ideas
| 18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
| Full Idea: We are able to reason about inconsistent beliefs, stories, and theories in useful and important ways | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 18789 | Intuitionist logic looks best as natural deduction [Mares] |
| Full Idea: Intuitionist logic appears most attractive in the form of a natural deduction system. | |
| From: Edwin D. Mares (Negation [2014], 5.5) |
| 18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
| Full Idea: In intuitionist logic each connective has one introduction and one elimination rule attached to it, but in the classical system we have to add an extra rule for negation. | |
| From: Edwin D. Mares (Negation [2014], 5.5) | |
| A reaction: How very intriguing. Mares says there are other ways to achieve classical logic, but they all seem rather cumbersome. |
| 18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
| Full Idea: One reason for wanting a three-valued logic is to act as a basis of a theory of presupposition. | |
| From: Edwin D. Mares (Negation [2014], 3.1) | |
| A reaction: [He cites Strawson 1950] The point is that you can get a result when the presupposition does not apply, as in talk of the 'present King of France'. |
| 18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
| Full Idea: The problem with material implication, and classical logic more generally, is that it considers only the truth value of formulas in deciding whether to make an implication stand between them. It ignores everything else. | |
| From: Edwin D. Mares (Negation [2014], 7.1) | |
| A reaction: The obvious problem case is conditionals, and relevance is an obvious extra principle that comes to mind. |
| 18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
| Full Idea: Among the virtues of classical logic is the fact that the connectives are related to one another in elegant ways that often involved negation. For example, De Morgan's Laws, which involve negation, disjunction and conjunction. | |
| From: Edwin D. Mares (Negation [2014], 2.2) | |
| A reaction: Mares says these enable us to take disjunction or conjunction as primitive, and then define one in terms of the other, using negation as the tool. |
| 18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
| Full Idea: On its standard reading, excluded middle tells us that bivalence holds. To reject excluded middle, we must reject either non-contradiction, or ¬(A∧B) ↔ (¬A∨¬B) [De Morgan 3], or the principle of double negation. All have been tried. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
| Full Idea: If we treat disjunction in the standard way and take the negation of a statement A to mean that A is false, accepting excluded middle forces us also to accept the principle of bivalence, which is the dictum that every statement is either true or false. | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: Mates's point is to show that passively taking the normal account of negation for granted has important implications. |
| 18782 | The connectives are studied either through model theory or through proof theory [Mares] |
| Full Idea: In studying the logical connectives, philosophers of logic typically adopt the perspective of either model theory (givng truth conditions of various parts of the language), or of proof theory (where use in a proof system gives the connective's meaning). | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: [compressed] The commonest proof theory is natural deduction, giving rules for introduction and elimination. Mates suggests moving between the two views is illuminating. |
| 18783 | Many-valued logics lack a natural deduction system [Mares] |
| Full Idea: Many-valued logics do not have reasonable natural deduction systems. | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
| Full Idea: Situation semantics for logics consider not what is true in worlds, but what information is contained in situations. | |
| From: Edwin D. Mares (Negation [2014], 6.2) | |
| A reaction: Since many theoretical physicists seem to think that 'information' might be the most basic concept of a natural ontology, this proposal is obviously rather appealing. Barwise and Perry are the authors of the theory. |
| 18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
| Full Idea: The difference between the principle of consistency and the principle of non-contradiction is that the former must be stated in a semantic metalanguage, whereas the latter is a thesis of logical systems. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
| Full Idea: For the intuitionist, talk of mathematical objects is rather misleading. For them, there really isn't anything that we should call the natural numbers, but instead there is counting. What intuitionists study are processes, such as counting and collecting. | |
| From: Edwin D. Mares (Negation [2014], 5.1) | |
| A reaction: That is the first time I have seen mathematical intuitionism described in a way that made it seem attractive. One might compare it to a metaphysics based on processes. Apparently intuitionists struggle with infinite sets and real numbers. |
| 8143 | 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. |
| 8147 | 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! |
| 8155 | 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? |
| 18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
| Full Idea: In 'situation semantics' individuals, properties, facts, and events are treated as abstractions from situations. | |
| From: Edwin D. Mares (Negation [2014], 6.1) | |
| A reaction: [Barwise and Perry 1983 are cited] Since I take the process of abstraction to be basic to thought, I am delighted to learn that someone has developed a formal theory based on it. I am immediately sympathetic to situation semantics. |
| 8142 | 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. |
| 7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
| Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom. | |
| From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88) | |
| A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate'). |
| 8151 | 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. |
| 8153 | 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. |
| 8154 | 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. |
| 8148 | 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? |
| 8144 | 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? |
| 8152 | 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. |
| 8156 | 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. |
| 8157 | 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. |
| 8159 | 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). |
| 8145 | 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. |
| 8149 | 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. |
| 8158 | 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. |
| 8146 | 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. |
| 8150 | 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? |