43 ideas
| 20678 | The Scientific Revolution was the discovery of our own ignorance [Harari] |
| Full Idea: The great discovery of the Scientific Revolution was that humans do not know the answers to their most important question. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 14 'Ignoramus') | |
| A reaction: I think of that revolution as raising the bar in epistemology, but this idea gives a motivation for doing so. Why the discovery then, and not before? |
| 20686 | For millenia people didn't know how to convert one type of energy into another [Harari] |
| Full Idea: For millenia people didn't know how to convert one type of energy into another, …and the only machine capable of performing energy conversion was the body. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 17 'Intro') | |
| A reaction: Hence the huge and revolutionary importance of the steam engine and the electricity generator. |
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| Full Idea: Today we expect that anything worth calling a definition should imply a semantics. | |
| From: Ian Hacking (What is Logic? [1979], §10) | |
| A reaction: He compares this with Gentzen 1935, who was attempting purely syntactic definitions of the logical connectives. |
| 12129 | 'Truth' may only apply within a theory [Kuhn] |
| Full Idea: 'Truth' may, like 'proof', be a term with only intra-theoretic applications. | |
| From: Thomas S. Kuhn (Reflections on my Critics [1970], §5) | |
| A reaction: I think we can blame Tarski (via Quine, Kuhn's teacher) for this one. I take it to be an utter failure to grasp the meaning of the word 'truth' (and sneakily substituting 'satisfaction' for it). For a start, we have to compare theories on some basis. |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| Full Idea: 'Dilution' (or 'Thinning') provides an essential contrast between deductive and inductive reasoning; for the introduction of new premises may spoil an inductive inference. | |
| From: Ian Hacking (What is Logic? [1979], §06.2) | |
| A reaction: That is, inductive logic (if there is such a thing) is clearly non-monotonic, whereas classical inductive logic is monotonic. |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| Full Idea: If A |- B and B |- C, then A |- C. This generalises to: If Γ|-A,Θ and Γ,A |- Θ, then Γ |- Θ. Gentzen called this 'cut'. It is the transitivity of a deduction. | |
| From: Ian Hacking (What is Logic? [1979], §06.3) | |
| A reaction: I read the generalisation as 'If A can be either a premise or a conclusion, you can bypass it'. The first version is just transitivity (which by-passes the middle step). |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| Full Idea: Only the cut rule can have a conclusion that is less complex than its premises. Hence when cut is not used, a derivation is quite literally constructive, building up from components. Any theorem obtained by cut can be obtained without it. | |
| From: Ian Hacking (What is Logic? [1979], §08) |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| Full Idea: I don't believe English is by nature classical or intuitionistic etc. These are abstractions made by logicians. Logicians attend to numerous different objects that might be served by 'If...then', like material conditional, strict or relevant implication. | |
| From: Ian Hacking (What is Logic? [1979], §15) | |
| A reaction: The idea that they are 'abstractions' is close to my heart. Abstractions from what? Surely 'if...then' has a standard character when employed in normal conversation? |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| Full Idea: First-order logic is the strongest complete compact theory with a Löwenheim-Skolem theorem. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| Full Idea: Henkin proved that there is no first-order treatment of branching quantifiers, which do not seem to involve any idea that is fundamentally different from ordinary quantification. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: See Hacking for an example of branching quantifiers. Hacking is impressed by this as a real limitation of the first-order logic which he generally favours. |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| Full Idea: Second-order logic has no chance of a completeness theorem unless one ventures into intensional entities and possible worlds. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| Full Idea: My doctrine is that the peculiarity of the logical constants resides precisely in that given a certain pure notion of truth and consequence, all the desirable semantic properties of the constants are determined by their syntactic properties. | |
| From: Ian Hacking (What is Logic? [1979], §09) | |
| A reaction: He opposes this to Peacocke 1976, who claims that the logical connectives are essentially semantic in character, concerned with the preservation of truth. |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| Full Idea: For some purposes the variables of first-order logic can be regarded as prepositions and place-holders that could in principle be dispensed with, say by a system of arrows indicating what places fall in the scope of which quantifier. | |
| From: Ian Hacking (What is Logic? [1979], §11) | |
| A reaction: I tend to think of variables as either pronouns, or as definite descriptions, or as temporary names, but not as prepositions. Must address this new idea... |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| Full Idea: A Löwenheim-Skolem theorem holds for anything which, on my delineation, is a logic. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: I take this to be an unusually conservative view. Shapiro is the chap who can give you an alternative view of these things, or Boolos. |
| 6809 | Kuhn came to accept that all scientists agree on a particular set of values [Kuhn, by Bird] |
| Full Idea: Kuhn later came to accept that there are five values to which scientists in all paradigms adhere: accuracy; consistency with accepted theories; broad scope; simplicity; and fruitfulness. | |
| From: report of Thomas S. Kuhn (Reflections on my Critics [1970]) by Alexander Bird - Philosophy of Science Ch.8 | |
| A reaction: To shake off the relativism for which Kuhn is notorious, we should begin by asking the question WHY scientists favoured these particular values, rather than (say) bizarreness, consistency with Lewis Carroll, or alliteration. (They are epistemic virtues). |
| 12128 | In theory change, words shift their natural reference, so the theories are incommensurable [Kuhn] |
| Full Idea: In transitions between theories words change their meanings or applicability. Though most of the signs are used before and after a revolution - force, mass, cell - the ways they attach to nature has changed. Successive theories are thus incommensurable. | |
| From: Thomas S. Kuhn (Reflections on my Critics [1970], §6) | |
| A reaction: A very nice statement of the view, from the horse's mouth. A great deal of recent philosophy has been implicitly concerned with meeting Kuhn's challenge, by providing an account of reference that doesn't have such problems. |
| 20692 | Money does produce happiness, but only up to a point [Harari] |
| Full Idea: An interesting conclusion (from questionnaires) is that money does indeed bring happiness. But only up to a point, and beyond that point it has little significance. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 19 'Counting') | |
| A reaction: The question is whether that flattening-off point is relative to those around us, or absolute, according to the needs of living. Though these two may not be separate. |
| 20663 | If a group is bound by gossip, the natural size is 150 people [Harari] |
| Full Idea: Sociological research has shown that the maximum 'natural' size of a group bound by gossip is about 150 individuals. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 02 'Legend') | |
| A reaction: On the other hand, most of us can learn the names of a group of about 450. Maybe the 'known' group and the 'gossip' group are equally significant. Not much use for a modern state, but of interest to communitarians. |
| 20677 | Since 1500 human population has increased fourteenfold, and consumption far more [Harari] |
| Full Idea: In the year 1500 there were about 500 million Homo sapiens in the world. Today there are 7 billion. …Human population has increased fourteenfold, our production 240-fold, and energy consumption 115-fold. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 14 'Discovery') | |
| A reaction: We really need to grasp how extraordinary this is. |
| 20688 | People 300m tons; domesticated animals 700m tons; larger wild animals 100m tons [Harari] |
| Full Idea: The combined mass of homo sapiens is about 300 million tons; the mass of all domesticated farmyard animals is about 700 million tons; the mass of the surviving larger wild animals (from porcupines up) is less than 100 million tons. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 18 'Permanent') | |
| A reaction: These really are figures that deserve much wider currency. Every school entrance hall needs a board with a few of the basic dramatic statistics about human life on Earth. |
| 20674 | The Nazi aim was to encourage progressive evolution, and avoid degeneration [Harari] |
| Full Idea: The main ambition of the Nazis was to protect humankind from degeneration and encourage its progressive evolution. …Given the state of scientific knowledge in 1933, Nazi beliefs were hardly outside the pale. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Worship') | |
| A reaction: It still sounds a fairly worthy ambition, close to the heart of educationalists everywhere. The problems start with the definition of 'degeneration' and 'progress'. |
| 20679 | We stabilise societies with dogmas, either of dubious science, or of non-scientific values [Harari] |
| Full Idea: Modern attempts to stabilise the sociopolitical order either declare a scientific theory (such as racial theories for Nazis, or economic ones for Communists) to be an absolute truths, or declare non-scientific dogmas (such as liberal values) | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 14 'Ignoramus') | |
| A reaction: [compressed] |
| 20690 | The state fostered individualism, to break the power of family and community [Harari] |
| Full Idea: States and markets use their growing power to weaken the bonds of family and community. They made an offer that couldn't be refused - 'become individuals' (over marriage, jobs and residence). The 'romantic individual' is not a rebel against the state. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 18 'Collapse') | |
| A reaction: [compressed] See the film 'Breaking the Waves'. An interesting slant on the Romantic movement. See Wordsworth's 'Michael'. Capitalism needs shoppers with their own money, and a mobile workforce. |
| 20689 | In 1750 losing your family and community meant death [Harari] |
| Full Idea: A person who lost her family and community around 1750 was as good as dead. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 18 'Collapse') | |
| A reaction: This is a very good advert for liberal individualism, and marks the downside of 'too much community'. |
| 20681 | The sacred command of capitalism is that profits must be used to increase production [Harari] |
| Full Idea: In the new capitalist creed, the first and most sacred commandment is: The profits of production must be reinvested in increasing production. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 16 'Growing') | |
| A reaction: In this sense, capitalism is less greedy than its predecessors. 17th century aristocratic monopolists simply spent the profits of their activities. See the gorgeous clothes then (and pyramids and palaces), and the quiet suits of capitalists. |
| 20682 | The main rule of capitalism is that all other goods depend on economic growth [Harari] |
| Full Idea: The principle tenet of capitalism is that economic growth is the supreme good, or at least a proxy for it, because justice, freedom, and even happiness all depend on economic growth. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 16 'Growing') | |
| A reaction: In this respect, the main opponent of captitalism is green politics, rather than marxism. |
| 20683 | The progress of capitalism depends entirely on the new discoveries and gadgets of science [Harari] |
| Full Idea: The history of capitalism is unintelligible without taking science into account. …The human economy has managed to keep on going only thanks to the fact that scientists come up with a new discovery or gadget every few years. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 16 'Growing') | |
| A reaction: For example, the desperate but unconvincing attempts to persuade us of the novelty of new models of car. Built-in obsolescence is needed once a design becomes static. |
| 20687 | In capitalism the rich invest, and the rest of us go shopping [Harari] |
| Full Idea: The supreme commandment of the rich is 'invest!', and the supreme commandment of the rest of us is 'buy!' | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 17 'Age') | |
| A reaction: Hence not only do the rich get much richer, while most of us remain roughly where we were, but there is a huge gulf between the investors and the non-investors. Encouraging small investors is a step forward. |
| 20685 | No market is free of political bias, and markets need protection of their freedoms [Harari] |
| Full Idea: There is no such thing as a market free of all political bias, …and markets by themselves offer no protection against fraud, theft and violence. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 16 'Cult') | |
| A reaction: Is this in theory, or in practice? In Sicily the free market has been a tool of the mafia. |
| 20693 | Freedom may work against us, as individuals can choose to leave, and make fewer commitments [Harari] |
| Full Idea: The freedom we value so highly may work against us. We can choose our spouses, friends and neighbours, but they can choose to leave us. With the individual wielding unprecedented power to decide her own path, we find it ever harder to make commitments. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 19 'Counting') | |
| A reaction: This is the worry of the communitarian. I take freedom to be a great social virtue - but an overrated one. |
| 20691 | Real peace is the implausibility of war (and not just its absence) [Harari] |
| Full Idea: Real peace is not the mere absence of war. Real peace is the implausibility of war. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 18 'Pax') | |
| A reaction: I have a nasty feeling that war only becomes implausible because it hasn't happened for a long time. War looked implausible for Britain in 1890. War certainly now looks implausible in western Europe. |
| 20684 | Financing is increasingly through credit rather than taxes; people prefer investing to taxation [Harari] |
| Full Idea: The European conquest of the world was increasingly financed through credit rather than taxes. …Nobody wants to pay taxes, but everyone is happy to invest. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 16 'Columbus') | |
| A reaction: This is presumably the mechanism that drives the unstoppable increase of the gulf between the rich and the poor in modern times. With investment, the rich get richer. |
| 20675 | The more you know about history, the harder it becomes to explain [Harari] |
| Full Idea: A distinguishing mark of history is that the better you know a historical period, the harder it becomes to explain why things happened one way and not another. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 13 'Hindsight') | |
| A reaction: Presumaby that means it resembles statistics. Each individual reading is perplexing, but some patterns emerge on the large scale. |
| 20676 | History teaches us that the present was not inevitable, and shows us the possibilities [Harari] |
| Full Idea: We study history not to know the future but to widen our horizons, to understand that our present situation is neither natural nor inevitable, and the we consequently have many more possibilities before us than we can imagine. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 13 'Hindsight') | |
| A reaction: On the whole winners forget history, and losers are branded through and through with it. If you don't know history, you can never understand the latter group. |
| 20671 | In order to explain both order and evil, a single evil creator is best, but no one favours that [Harari] |
| Full Idea: Monotheism explains order but not evil, and dualist religion explains evil but not order. One logical solution is a single omnipotent God who created the universe, and is evil - but nobody in history has had much stomach for that belief. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Battle') | |
| A reaction: Eh? Is there not also good, which also needs explaining? And there is some chaos to be explained too. Hume offers the best explanations. An inexperienced god, a team of squabbling gods, a god with shifting moods…. Study the facts first. |
| 20664 | Animism is belief that every part of nature is aware and feeling, and can communicate [Harari] |
| Full Idea: Animism is the belief that almost every place, every animal, every plant and every natural phenomenon has awareness and feelings, and can communicated direct with humans. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 03 'Talking') | |
| A reaction: So does this count as a 'supernatural' belief system? It seems not, if the awareness is integral to the natural feature, and dies with it. Panpsychism is not supernatural either. A problem for anyone trying to define Naturalism. |
| 20666 | Most polytheist recognise one supreme power or law, behind the various gods [Harari] |
| Full Idea: Polytheism does not necessarily dispute the existence of a single power or law governing the entire universe. Most poytheist and even animist religions recognised such a supreme power that stands behind all the different gods, demons and holy rocks. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Benefits') | |
| A reaction: Presumably this one supreme power was always taken to be too remote for communication or worship. Are the other gods seen as slaves, or friends, or ambassadors of the Supreme One? |
| 20667 | Polytheism is open-minded, and rarely persecutes opponents [Harari] |
| Full Idea: Polytheism is inherently open-minded, and rarely persecutes 'heretics' and 'infidels'. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Benefits') | |
| A reaction: The Old Testament tells of the Jews turning on local pagans, and India was presumably tolerant Hindus encountering less tolerant Muslims. Then there's Christians in Africa. Dreadful bunch, the monotheists. Romans killed very few Christians. |
| 20665 | Mythologies are usual contracts with the gods, exchanging devotion for control of nature [Harari] |
| Full Idea: Much of ancient mythology is a legal contract in which humans promise everlasting devotion to the gods in exchange for mastery over plants and animals. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Silencing') | |
| A reaction: [He cites the first book of Genesis] So how readily do you swith allegiance, if someone else's gods are more successful? Why be loyal a loser. It should be like shopping - but I bet it wasn't. |
| 20669 | Dualist religions see everything as a battleground of good and evil forces [Harari] |
| Full Idea: Polytheism gave birth to monotheism, and to dualistic religions. Dualism explains that the entire universe is a battleground between good and evil forces, and everything that happens is part of that struggle. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Battle') | |
| A reaction: Presumably we are supposed to support the good guys, so the gods are not equals. God v Satan seems the right model, but Satan has to be beyond God's control, or else the problem of evil has to be solved. Empedocles held something like this. |
| 20670 | Dualist religions say the cosmos is a battleground, so can’t explain its order [Harari] |
| Full Idea: Dualist religions solve the problem of evil, but are unnerved by the Problem of Order. …If Good and Evil battle for control of the world, who enforces the laws governing this cosmic war? | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Battle') | |
| A reaction: You might explain it if one side was persistently winning, which is roughly God v Satan. |
| 20673 | Manichaeans and Gnostics: good made spirit, evil made flesh [Harari] |
| Full Idea: Manichaeans and Gnostics argued that the good god created the spirit and the soul, whereas matter and bodes are the creation of the evil god. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'Battle') | |
| A reaction: Hm. What motivated the evil god to do that? The evil god's achievement looks a lot more impressive. |
| 20668 | Monotheism appeared in Egypt in 1350 BCE, when the god Aten was declared supreme [Harari] |
| Full Idea: The first monotheist religion known to us appeared in Egypt c.1350 BCE, when Pharaoh Akenaten declared that one of minor deities of the Egyptian pantheon, the god Aten, was in fact the supreme power ruling the universe. | |
| From: Yuval Noah Harari (Sapiens: brief history of humankind [2014], 12 'God') | |
| A reaction: Zeus seems to have started like a tribal chief, and eventually turned into something like God. |