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Slide 1:Universals
Slide 2:Metaphysics ????
Metaphysics asks about the nature of things Common notions, things we usually take for granted, are subject to a stringent examination. For example, we ask about the nature of existence, the concept of persistence, the concept of identity, the difference between properties and objects, etc.
Slide 3:Ancient Aristotelian scholars first coined the word metaphysics: it names the work written by Aristotle just after his work on physics: meta means after. In the book Metaphysics, Aristotle highlights the subject to be the study of being qua being.
Slide 4:For the contemporaries, a study of beings may be the province of physics because physics studies the most fundamental constituents of all matters. In ancient times, due to the lack of scientific knowledge, philosophers believed that earth, air, water and fire are the four fundamental substances.
Slide 5:Consider the following terms: 1. Substance 2. Matter 3. Being 4. Existent 5. Form 6. Stuff 7. Thing 8. Whole 9. Part 10. Simple 11. Element 12. Object
Slide 6:Usually, we think that the way we talk about the world reflects the way the world is: consider the 1:1 model that mimics the actual thing. But somehow we also think that the basic form of the world is given by the expression some thing has this or that feature. So, we have the dichotomy between the thing and the features possessed by the thing. The features of things are called properties. But by intuition, are you sure that you can tell the difference between a thing and its features?
Slide 7:Properties
John is tall. From the above simple sentence, we know that John has the property of tallness. In grammatical terms, properties are what our adjectives and predicates refer to.
Slide 8:But can we say things the other way round? Such as Tallness is John? Of course there are always cases where we fail to distinguish between subject and properties by the above grammatical rules.
Slide 9:From This apple is red, can we say the same thing with Redness is in this apple? But it sounds awkward to reason that the property of appleness is true of this redness. Why can we say that the apple has the property of redness?
Slide 10:Particular and Universal
A particular is thing that can have properties but cannot have other particulars A universal is something that is repeatable Other ways of distinguishing the two, for example, are that a particular is concrete, fixed by space-time and that a universal is abstract and beyond space-time.
Slide 11:One over many
The problem of universals can be traced back to Plato and he labeled the problem as the problem of one over many. Put it simply, Plato asks why the universal redness, for example, can be present in the many red things.
Slide 12:Realism
To solve the problem, Platonic realism holds the view that a universal is an abstract entity that can be related to each individual particular. This seems to contradict our commonsensical notion of what something is: can something be really some thing if it is abstract, non-physical and beyond space-time?
Slide 13:Platos main targets of analysis are universals such as wisdom, goodness, beauty, justice and courage, etc. In English grammar, when we turn an adjective into noun, we make it a general term such as goodness. The problem is: do we have something to correspond to these general terms (just as the term water has the H2O molecules for correspondence), or is it just a manner of expression? We may laugh at those who seek for goodness as if they were looking for a specimen in science.
Slide 14:Ontological commitment of realism
1) The relation between universal and particular is instantiation (exemplification): a universal can be instantiated by many particulars. For example, we say that the universal beauty is instantiated by the flowers, the Miss Hong Kongs, the LV bags, etc. Is instantiation the same as possession? If so, how?
Slide 15:2) Universals are abstract. We can of course think about the abstract without also thinking about the concrete things that instantiate the abstract.
Slide 16:3)Existence Universals exist in the same sense as you exist. It is not just a manner of saying things. For Plato the perfect Forms exist eternally somewhere.
Slide 17:You must have had this impression many times before: it is quite okay for you to recite things, the special terms, the facts, etc. But you are horrified when your teachers ask you to explain how you make sense of even simple things. For example, if asked why an electron is negatively charged, you just reply that it is so by definition. But when further asked what will happen if an electron really loses its negative charge, you might reply that it has been destroyed and something new comes into being.
Slide 18:Platos theory of universals is famously given in the classic Republic. In this work, he uses the allegory of the cave to point out that common people are accustomed to illusion or appearance. The things we see and believe to exist are just poor imitation of the real things. For example, the wisdom that we see in the politicians are very bad demonstration of true wisdom, and so on. For science students, the cell that they see in a microscope is not what is actually the case: we can use more and more powerful microscope to see the same thing as having many different aspects.
Slide 19:Platos concern can be simplified as the question of what underlies or binds together the many things that have the same feature? It cannot be mere mistake or similarity. He proposes the most famous and yet most odd explanation: the theory of Form.
Slide 20:For Plato, the proper explanation of why the many earthly things can share the same property is that there is really a Form in a non-worldly realm. For example, there is an ideal Form of redness somewhere else such that the earthly red things all imitate with partial success that Form. So, the imitation explains the fact that earthly red things all look red in a rough and general way. But they are not identically red.
Slide 21:If you believe the rather fanciful theory of Plato, then you could understand why he advises the people in the cave, in other words normal people like us, to abandon the knowledge of the imitation in order to progress to the knowledge of the perfect Form. In this understanding, there is the contrast between ordinary sensory knowledge and absolute knowledge of the Form. To know the Form, we have to use, so to speak, the minds eyes, nous.
Slide 22:Of course, we can easily understand one example of Platos intuitive knowledge of the Form in the case of our grasp of, say, triangularity. No one has ever seen a perfectly drawn triangle and yet most of us understand what a triangle is. Even blind person can intuit the meaning of triangularity. So if this example works, it seems that other general terms can be explained by Platos theory.
Slide 23:The problem with Platos theory is not mainly about the strangeness of an other-earthly realm. Rather, this theory harbors some inconsistency. For example, if two particulars instantiate the same Form of redness,
Slide 24:Third Man Argument
Slide 25:Nominalism
What seems to be a harmless way of talking turns out to be exceedingly unbelievable if we try to explain further. Therefore, some philosophers are determined not to play the realists game. The nominalists deny the need to talk about universals.
Slide 26:Nomina in Latin means name. Hence for the nominalists, only concrete individuals exist, whereas universals are just names. The extreme form of nominalism says that the name of a universal, such as redness, refers to the whole collection of concrete red things.
Slide 27:It looks fine until we ask a simple question: if there is no universal redness, how and why can we put all those red things together? After all, to be a useful name of a lot of things must presuppose some common properties amongst these things. Those properties are somehow considered real in the sense that they are part of the particulars.
Slide 28:Furthermore, if we dont understand properties and relations in the way the realists do, it seems that it is a surprising accident that we all label the red things as red. The underlying query is that there must be something inherent in the particular that makes it red.
Slide 29:If you have read David Armstrongs extract, you should have a good survey of his criticism of nominalism.
Slide 30:Ostrich Nominalism
This type of nominalism evades the question of what properties are.
Slide 31:Class Nominalism
If you have taken a course on logic, you should remember that two sets/classes are the same iff they have the same extension/members. This approach seems to solve the problem by taking individuals as basic and then use set/class as a way of grouping them. So, in a simplified way of explanation, a property is just a certain way of grouping a bunch of particulars.
Slide 32:But then, what is a class? Should the nominalists seriously explain the existence and nature of class? There is also the second problem of the coextensive properties: suppose two intuitively different properties do pick out the same members, do we then say that there is only one class or two?
Slide 33:Suppose we know that only and all of the SPACE students who get GPA 3.5 or above get into HKU by non-JUPAS, then should we consider the class The students who get into HKU by non-JUPAS and the class The SPACE students who get GPA 3.5 or above identical? Intuitively, the two ways of saying pick out different properties.
Slide 34:One way for the nominalists to solve the problem is to assume that there is another realm called the possible. Hence, although in actuality the two classes of students are identical, it is possible that they are not. But for Armstrong, this remedy is worse than the disease.
Slide 35:Strange Classes
If classes are arbitrary collections of particulars, they deviate from our intuition that there are shared properties we find significantly natural. So the class nominalists have to resort to the notion of natural classes or to allow that the class of red things is as significant as the class such as {1, hydrogen atoms, eggs}.
Slide 36:Resemblance Theory
Another way out is called resemblance theory. Let us suppose that it is unproblematic that each individual thing with various properties exists. We further suppose that each individual thing, with all its properties, is unique. Then we can argue that each unique thing with the properties together is called a trope.
Slide 37:Notice that there is no mentioning of the recurrence of universals since each existing trope is unique. Then we can explain that due to the resemblance between different tropes, we form the idea that there is a certain class of objects. Without the grasped similarity, each trope should be of its own class.
Slide 38:But do we also imply that resemblance is an subjective fact? If not, we seem to commit to the fact that there must be something in common between the different tropes.
Slide 39:Concept Nominalism
If you instead think that the world is dependent on our grasp of it as such, then maybe you can argue that redness is just a human concept. As a result, we human beings impose the concept of redness on different particulars because we share the same cognitive abilities and physiology, language, etc.
Slide 40:Imagine that there are aliens who communicate with us their concept of XYZ: they try to use our language to explain this concept, and to point to certain machines and samples, etc. But we can conceive that we might still fail to grasp the concept of XYZ. What we lack, therefore, is not intelligence; and it also does not point out that redness is a more real concept than XYZ. Rather, some concepts held natural by the aliens are not only unnatural by our light, they are also unknowable in the strong sense.
Slide 41:Some philosophers argue that there is no final verdict on most metaphysical questions. But they nevertheless give us some golden rules in understanding the world.
Slide 42:First, as we are used to avoid falsehood and mistakes, there is the need to simplify our way of understanding, if possible. For example, always opt for the answer that involves the least unexplained entities. So, ask yourself whether you need the existence of the soul to explain this world. If not, then the soul is a metaphysically suspicious and extravagant entity.
Slide 43:Some attribute this view to the Mediaeval scholar: Ockham. The principle is usually labeled Ockhams razor: do not multiply entities beyond necessity. For scientists, most of the rather odd-sounding entities such as quarks are real by necessity: they are required to explain certain phenomena.
Slide 44:In other subjects, when you are asked in exam to explain certain things, by following Ockhams razor, the best answer is always the one with the least unnecessary entities, the least complicated story, etc. In murder cases, the police also follow such principle: dont postulate the existence of accomplice unless indicated, always regard the culprit to be the victims acquaintance, etc.
Slide 45:To apply Ockhams razor to our problem, ask yourself whether the postulation of the existence of universals is strictly necessary.
Slide 46:Existence
This is a basic word. But ask yourself what do you mean by something existing. Is existence a property of things? If not, what does it express when we use it in the following sentence: Batman does not exist, but Obama does?
Slide 47:Kant famously said that existence is a pseudo-predicate. In other words, it does not help us to understand a thing better if we add the information that it exists. But what about the other way around when we assert that something does not exist? If that something does not exist, what is the thing we just referred to?
Slide 48:Bertrand Russell is famous for offering the following solution: If we assert The king of Hong Kong does not exist, we are not speaking nonsense, if we think that asserting the non-existence of things is absurd. Instead, the sentence, although it looks simple, is in fact a compound sentence.
Slide 49:There are in fact three basic sentences hidden in the original one. To simplify, we have: Whoever is a king does not rule over Hong Kong. Now this sentence is a lot clearer since it does not bring in a spurious entity called the king of Hong Kong. The moral to learn is that the original sentence is formally misleading: the subject term the king of Hong Kong does not actually, as the sentence superficially suggests, acts as a definite description or proper name such as the king of pop.
