Leibniz and the principle of the identity of indiscernibles

I agree that the Principle of the Identity of Indiscernibles (PII) doesn't seem, initially, to "do any work" in Leibniz's argument. I've been trying to get my head around what L. means and am beginning to understand what he is saying (I think). At first I thought PII was tautologous but on reflection my view has changed.

L. is using PII to argue that two indiscernible things could only be 'separated' by space and time, hence if there were indiscernible things separated by space and time then the properties of space and time become properties of the objects. L. doesn't want this argument to succeed, therefore he argues that there are no indiscernible things, in terms of all of their non space time properties.

I'm not sure I agree that L. doesn't use the Principle of Sufficient Reason. He is arguing that were the universe to be created earlier or in a different place, there would need to be a reason, and there couldn't be such a reason, therefore it couldn't happen? Again, if the universe were to be created in a different space or at a different time then space an time become properties of the objects and therefore have some absolute existence and are not merely relational.

Both arguments certainly stretch the thinking, but I was wrong to rush to judgement.

I do think however, that L.'s philosophy is driven by his Theology. I also agree with him that there probably aren't two indiscernible things (excluding their position in space and time) at the macro level but I'm not sure this achieves what L. wants.

It could be possible that space and time are both absolute and relative. I'm not sure whether it is fair to argue that these two views are mutually exclusive.

Are space and time absolute?

I suspect there may be some confusion (at least on my part!) regarding what we mean when we say space and time are absolute for the Leibniz type philosophical argument and the meaning of absolute used in the Einstein space/time sense. I think we possibly have two different types of absolute / relative distinctions going on.

For Einstein the argument is whether time is "fixed" and this sense of absolute is different. Einstein says no, time is relative to the observer.

For Leibniz the argument is whether time is absolute, i.e. exists independently of events that happen.
I don't think these two meanings of absolute relative are quite the same, but am happy to stand corrected as it is a fairly mind boggling subject!

If time is relative to the speed of light (which I accept) then could we not still say that time is absolute as far as Leibniz debate is concerned? If the speed of light is fixed, then in one sense time is also fixed in relation to the speed of light. Time is therefore the same everywhere, allowing for its relativity to the speed of light. Time is not something which is imposed by the mind, it is a real "thing" and depends on the speed of light and distance (i.e. not on events).

Similarly for space. Space may be able to bend, but it is still and absolute "thing" in one sense, again relative to the speed of light and time.

One interesting question, which I don't profess to know how to answer, would be will space still exist if there is nothing in the universe (i.e. the heat death of the universe). Once entropy has worked its wicked way to total finality, could we still talk about space?

Laws of nature

I have been reading the Stanford Encyclopædia article on the subject of laws of nature. The concept of universal laws is relevant to the philosophical problem of induction, and also comes into other metaphysical problems including epistemology and the philosophy of propositions.

It is interesting to try and define what "makes" a universal law. The account which I particularly like explains universal laws in terms of deductive systems, with strength and simplicity being the key characteristics of a universal law.

Another approach employs the philosophical concept of universals to analyse laws of nature. This view was set out by Armstrong as follows:
"Suppose it to be a law that Fs are Gs.F-ness and G-ness are taken to be universals. A certain relation, a relation of non-logical or contingent necessitation, holds between F-ness and G-ness. This state of affairs may be symbolized as‘N(F,G)’"

According to Stanford, the majority of contemporary philosophers are realists about laws; they believe that some reports of what the laws are succeed in describing reality. There are, however, some antirealists who disagree. More on that later.

Free will vs. determinism

What I believe (is obviously true) is that there is interaction between the mental world, where we have free will and the physical world, where the mental act leads us to influence the physical world. Once the physical world starts "moving", then laws of causation apply.

So if I decide to scratch my nose, I send signals to the muscles in my arm which raise my hand to my nose. If my hand then brushes a fly away, it's flight path is subject to the laws of cause and effect.
My free decision to scratch my nose was not pre-determined, it is not random, and it is the result of a free choice which is the origin of a string of cause and effect.

Hard determinists must find it impossible to discipline their children. If they have no free will then how can they blame them for bad behaviour?

The truth is that no-one really believes in hard determinism, they can't. That I think is why Peter Strawson starts his essay with the admission that he does not really understand what determinism is.
Philosophers who defend determinism often resort to a fallacious argument along the lines of "everything must have a physical cause" and then use a regress argument to show that free will cannot be the original cause. They come across like Berkeley did arguing for idealism, using rules they make up themselves (B.'s ideas must resemble their cause) to justify their chain of reasoning and ending up with a result which is contrary to common sense and denies the very nature of humanity.

Being wrong about colour

I think there can be two ways in which we can be wrong about a colour. One is if we subsequently realise that we were experiencing an optical illusion. The other is if other people convince us that we were experiencing an illusion.

In both cases what matters is coherence - a yardstick by which we can establish objective truth. Other people can only convince us that we were mistaken if their account is more coherent than our initial account.

So objective truth for me does not depend on the existence of an external world at all, but on the coherence of our views about the world.

Epiphenominalsim

Epiphenomenalism is the view that some ideas are epiphenomenal - that some ideas come about in the brain but have no effect on the physical world. This is closely related to the debate between materialists and idealists.

According to Stanford, "The central motivation for epiphenomenalism lies in the premise that anything that can causally contribute to a physical event must itself be a physical event. If a mental event is something other than a physical event, then for it to make any causal contribution of its own in the physical world would require a violation of physical law."
http://plato.stanford.edu/entries/epiphenomenalism/

The original argument that Jackson devised in Mary's room (explained in the Philosophy Bites podcast 'What Mary Knew') to show that materialism is inadequate to explain the way the world is concerned Mary, who even though she knew everything about the colour red in physical terms without actually having perceived it, would in effect not know what seeing red was actually like.
So the perception of red, or at least the qualia red, is a mental activity which is unrelated to physics in a sense.

So the red rose isn't really red at all (under a physicalist view), it is only when we perceive it that we get the qualia red in our mind (the idea). To tie this into Locke, under an epiphenomenalist view the rose doesn't cause the perception of red as Locke argued.

More on universals

One major idea behind medieval nominalism is that universals are not entities but concepts or general names (lat. nomina) that we use to pick out certain features of particulars.

I am in favour of the medieval approach

I see universals such as "red", "hot" and "north" as concepts which tie together the common properties of particulars, which are then named. So "north" becomes the concept which means closest to the north pole (of a magnet or of the Earth). I can't get my head round how north could be an entity in any other manner than a concept which describes a spacial relation or a rule for help in navigating. It may then acquire other meanings in language, but the first people to use the term north must have used it as a rule to describe that spacial relation, or perhaps to point to a particular place that is north of another place.

I have been trying to imagine a world without any people, to think through what implications that might have on my opinion about particulars and universals. In such a world I think we would still have particulars, but I'm not sure if we would have universals. As soon as we bring sentient beings into the world I think they must create universals, which implies to me that they must be man made.

However, picking up on Armstrong's view about scientific laws, I then thought that perhaps I am wrong! In a world without people we would still have "gravity" as a universal law, and so I switched back to thinking that universals are things which are, quite literally "universal". This may sound naive, it certainly does as I type it.

My only conclusion is that we can probably define "universal" to mean whatever we want. Since it is not an object we can point at, no-one can truly (or perhaps helpfully) say "No, your wrong, you don't actually mean what you just said".

From my previous course, I came down on the side of believing that there is some form of contradiction when we reject a universal law. Whether this contradiction is imposed by our understanding (Kant) or by our language (Wittgenstein) or is innate, I'm not sure. Perhaps it is all three.

I want to come down on the side of a simplistic approach, and say that universals apply to universal "things" such as either laws of nature, or concepts which apply everywhere and at every time (such as north, red, hot and even horse).

I like Armstrong's focus on truth-makers, but I think this allows for a large number of universals.
Whether these universals are man-made or "in" nature is still up for grabs. Hume would argue that we can never know whether they are "in" nature, and it does seem to be that you have to have an omniscient point of view in order to know the truth. This becomes an epistemological question.
From a metaphysical standpoint I want to say that universals exist as concepts, but I'm not sure whether we can say more about their ontological status.

Particulars and Universals

A few initial thoughts, as this is a new topic to me.

I am inclined to agree that universals do not have any kind of supernatural existence in a non physical / temporal realm. They also don't "exist" in time and space in terms of being something we can point to, because if that were the case they would be particulars.

But, as we saw in the previous modules, we can talk about things that don't exist in space and time in a meaningful way, and so they must have some kind of subsistence.

My initial reaction, having thought about how I would describe universals, is that they seem to be (or at least have their origin in) some kind of "rule" for describing things (either properties or relations).
We can all understand what someone means by "higher" or "redder". These are terms which help us to talk about particulars, and to understand what we mean when we want to convey complex ideas. So the universal "red" is a rule which allows us to ascribe a subjective sense experience (or perhaps a particular wavelength of light).

The universal "red" only seems to be of use in communication of some form. Without communication I'm not sure that universals serve much purpose.

Before the Big Bang

I have picked as an example of an ontological dispute the argument over whether there was something before the Big Bang. I am not a scientist and therefore my post will focus on the ways we might approach the question.

There are a number of competing theories about what happened before the Big Bang. It is unlikely (impossible?) that all of them are true. I conclude from this that we can formulate concepts which don't exist, if by exist we mean exist in space and time. But the concepts which turn out to be non-existent are not necessarily meaningless.

To be given serious (scientific) consideration, each hypothesis needs to be coherent and not contradicted (falsified) by experimental evidence. It is this coherence which allows the concept to have meaning, an incoherent or self-contradictory theory is either false or meaningless.
Many scientists believe that the Universe began at the Big Bang, estimated to have taken place 14 billion years ago. Was it at that point that space and time began? Some argue that there was nothing before the Big Bang. But it seems odd (incoherent?) to describe a scenario where there is no "before" (just as it is odd to think of no "after"). Kant would argue that our ideas of space and time are essential to our understanding of reality, I am inclined to agree with this view. I therefore instinctively reject the idea of a beginning of space and time as incoherent.

But is our idea of the existence of space and time dependent on the existence of light? If there was no energy before the Big Bang, and no light to travel at lightspeed, would there still be time? Does our idea of time require distance and speed to have meaning?

Modern science has developed theories about the "time" before the Big Bang by using quantum physics. But even if we devise a theory which gains widespread acceptance, does this mean we would regard it as "true". In the absence of time travel how would we know?

My final comment is that some people prefer a supernatural explanation; for them, some questions are not answerable scientifically.

Plato's cave

The analogy of the cave is used by Plato to point the way to towards a new discipline - the discipline of metaphysics.

By pointing out that a higher level of understanding is attainable, and by drawing a distinction with a life lived in ignorance of this higher level, Plato is making a case for allowing philosophers to pursue their interest in metaphysics, for the good of everyone.

The prisoners in the cave have a limited understanding of their world, this is not because they are not intelligent or perceptive enough to achieve that understanding, but because they are (literally) chained. The analogy with philosophy is that philosophers are chained by their failure to ask the right questions and look in the right direction. If they were to think about the right things (e.g. Forms) they would be freed from their metaphorical chains and thereby have access to a whole new level of understanding about the world.

Plato's Forms

Plato develops his theory of Forms in order to try and explain how things that we experience are the way they are.

Plato's theory has an extremely wide scope - it is aimed at addressing a number of fundamental metaphysical questions including:

• how do we explain resemblance?
• the problem of universals (the question of whether properties exist, and if so, what they are)?
• what do we mean by matter and substance?
• what is change?

Plato's answer to these questions is a concept he calls "Forms". Forms transcend experience, are permanent and never changing. It is "from" Forms that the material world is the way it is. Forms therefore help explain the material world. The process by which this takes place is very obscure, necessarily so since the Forms are not objects of experience.
The argument for the existence of Forms seems to be abductive, inference to the best explanation.
The key issue for me in debating Forms is to try and understand what Plato actually thinks they are, this is not an easy question!

Change

I have started 'Reality, Being and Existence: An Introduction to Metaphysics'. There are 36 people on the course, which is a good number and considerably more than on my previous two courses. Students come from all around the World, including DRC, which I think must be a first.

As part of the introduction I have been contemplating the concept of change.

Firstly, there seems to be a very close relationship between the idea of change and the idea of time. It seems that any definition of change needs to refer to or utilise the idea of time. I can't see any way of explaining change other than by using the concept of time. 'States of affairs being different at different times' is a simplistic way of defining change, but captures the essence of the concept.
I also think that the idea that time is bi-directional, we can talk about time moving forwards and time moving backwards. Times arrow shows us that time moves in one direction in the physical universe. This idea seems to be related to entropy. It is generally accepted that the universe displays entropy as a universal law, and that this entropy shows us the direction in which times arrow points.
The status of the arrow of time seems to be a fundamental metaphysical question. This leads to some fascinating ideas such as time travel and whether time has a beginning or end.

Next course

I have signed up for the Hilary Term Introduction to Metaphysics course, which starts in January.

More to follow soon.

Realism

Is the statement that "we cannot abstract out our own perspective from our view of the external world" a fatal blow to realism?

Even if the statement were true, it would not speak "conclusively" to truth or falsity of an external world. The statement is not a metaphysical statement but an epistemological statement. It says "we cannot know if an external world exists", rather than "an external world does not exist". I do not believe it is possible to reach such a fundamental metaphysical conclusion based on this epistemological proposition.

I also believe that the statement is incorrect. I believe it is possible, in one very important sense, to abstract our own perspective from our view of the external world.
What we think we know about the world is not just taken from our own experience or perspective. Our knowledge of the world is built from the shared experiences of millions of people, written down and recorded over history. The process of scientific discovery is by its very nature the process of abstracting our own perspective from our view of the external world.

We don't just passively experience things in real-time through our five senses and then later recall these experiences via our memory. We are also blessed with the power of reason. I think that by our powers of reason we provide structure to the external world and that the only coherent explanation of why and how this works is that the external world must have structure and exist independently of us.
I think a realist approach is the only credible and coherent approach to take - I look upon rejections of realism as somewhat "trivial" attempts to twist logic and reason into reaching an absurd conclusion.
It is my view that the burden of proof lies with those that reject realism - is there any good reason to think that the external world does not exist? The subjectivity of secondary qualities is easily explained, and rather than casting doubt on the existence of things in themselves, it lends support to the common-sense realist approach that the external world does exist.

Locke and Berkeley

Does Locke or Berkeley give a better account of the primary/secondary property distinction?
I think neither Locke nor Berkeley give a wholly satisfactory explanation of primary and secondary qualities but tend towards Locke having a slightly more coherent view.

In favour of Locke, I can understand the distinction he draws between those qualities which are less prone to subjective "distortion". Physical extension, number, motion and even place in time seem to be "qualities" which are of a somewhat different nature from taste, smell, colour etc. Secondary qualities tend to be highly subjective and depend very much on the "point of view" of the subject.
I reject however, Locke's belief that secondary qualities are "nothing in the objects themselves". There is something (a physical quality) in objects over and above a "power" to produce certain sensations in sentient beings. I believe that our sensations are in fact caused by physical properties of objects and we directly perceive that quality, but the precise nature of our perception depends on the circumstances under which we perceive it.

Locke thinks that a sharp pin having the power to cause the idea of pain is analogous to a tomato having the power to cause the idea of red. I don't think these two example are really comparable in the way Locke does. Pain is not a quality of a pin - sharpness is the quality of the pin which compares to the redness of a tomato.

Berkeley does not make a convincing case for either his epistemological or metaphysical claims. I flatly reject his claim that we cannot abstract qualities. I also reject his proposition that all ideas are entirely dependent on minds. He thinks that ideas are caused by God whereas are more coherent view is that ideas are caused by the external world. Berkeley has no clear conception of what God is, and whether there is only one God or many. Since we cannot have an idea of what God is other than the cause of all ideas I think it makes more sense to replace God with an external world. I accept that in a very strict sense this is an assumption, but feel that the burden of proof lies with those that claim the external world does not exist.

Philosophy of language

I am struggling to understand what Schopenhauer could mean by his definition of free will. Unfortunately, he doesn't give examples or put the way he uses the term in context, so I suspect Wittgenstein would have some difficulty accepting that it is truly meaningful.

I have recently been watching the excellent videos on the philosophy faculty website:
http://www.philosophy.ox.ac.uk/podcasts/general_philosophy
In part 5 Peter Millican touches on free will a few times, in particular in relation to the mind / body dualism debate. He makes a very interesting analogy. If we try and think about ourselves in terms of a computer, we have hardware (which explains our physical actions in terms of cause and effect) which extends to the physical and chemical constituents of our brains. We also we have software, which is analogous to our minds.

We cannot fully explain our minds by just talking about physical properties or causation. Using this analogy I would maintain that our minds are programmed in such a way that we are free to make moral choices and decisions. I can't explain why this is the case, but I certainly do believe that it is the case.
I think looking at the way we use the words "free will" helps, but Schopenhauer seems to be looking for a metaphysical explanation of what free will is, whereas explaining the terms by how they are used seems to be edging towards an epistemological explanation.

Is it possible to answer metaphysical questions by looking at the philosophy of language?

Hume's Treatise

The Ninth Edition Britannica article on Hume is written by Robert Adamson, Professor of Logic and Philosophy at Owens College (Victoria University of Manchester) and subsequently at the Universities of Aberdeen and Glasgow.

Adamson argues that, despite Hume's subsequent discounting of his Treatise, through its "freshness and concentrated vigour" Hume is at his best in his first major work. According to Adams, "none of the principles of the Treatise are given up in later writings, and no additions are made to them". While this is debateable, it serves to underline the prominent place that the Treatise must hold for students of Hume.

Hume sent a copy of the Treatise to Butler, who as we have already noted was of some influence to Hume's thinking. Hume ranks Butler alongside Locke and Berkeley as the originators of the experimental method in moral science; Butler warmly commended Hume's essay to his friends. Both share Hume's sceptical conclusions regarding belief in matters of fact. Butler however,  retains confidence in the rational proofs for the existence of God alongside an a priori view of conscience.

I will no doubt return to arguments for and against the existence of God in later posts, but it is interesting to note that Hume's Dialogues Concerning Natural Religion was published posthumously in 1779, originally with neither the author's nor the publisher's name.

The title page of the Treatise from the 1739 edition contains the following:

A Treatise of Human Nature : Being an Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects.

Rara temporum ƒelicitas, ubi ƒentire, quæ velis; quæ ƒentias, dicere licet.

One of the regrets of my comprehensive school education is that I was not given the opportunity to study Latin or Greek. Fortunately, Google came up with the meaning of the quotation from Tacitus: "Rare are the times you can, in turn, feel what you want and say what you feel. Try it."

Introduction to the Treatise

The opening sentence of the Introduction is as follows: "Nothing is more usual and more natural for those, who pretend to discover any thing new to the world in philosophy and the sciences, than to insinuate the praises of their own systems, by decrying all those, which have been advanced before them."

The opening sentence might lead one to suspect that Hume is not going to follow this path, but as you read further you realise that in fact, this is exactly what Hume is setting out to do.

"Principles taken upon trust, consequences lamely deduced from them, want of coherence in the parts, and of evidence in the whole, these are every where to be met with in the systems of the most eminent philosophers, and seem to have drawn disgrace upon philosophy itself."

So Hume is attempting to come up with a whole system of philosophy, and is not merely commenting on previous attempts. This is why I admire Hume, the scope and originality of his Treatise is very impressive.

Hume goes on to point out that in philosophical debates "'Amidst all this bustle, 'tis not reason which carries the prize, but eloquence....The victory is not gained by the men at arms, who manage the pike and the sword; but by the trumpeters, drummers and musicians of the army". Here we get a clear "heads-up" that Hume is going to attempt to cut through the eloquence of his predecessors, which presumably hides their muddled thinking, and shine a light of reason on human nature. I find this amusing, given that Hume himself is so eloquent.

Hume's objective is to address the questions of metaphysics. He acknowledges that this is not going to be easy: "For if truth be at all within the reach of human capacity, 'tis certain it must lie very deep and abstruse".

Next, Hume stresses the connection between all of the sciences and the science of Man, i.e. Human Nature. By improving our understanding of metaphysics, he will no doubt have a significant influence on all other branches of human knowledge. Again, we begin to see the ambition of Hume's project - he isn't messing about on the periphery! Hume puts this very clearly: "In pretending therefore, to explain the priciples of human nature, we in effect propose a compleat system of the sciences, built on a foundation almost entirely new, and the only one upon which they can stand with any security."

Next, Hume introduces the importance of experience and observation, the scientific method: "And as the science of man is the only solid foundation for the other sciences, so the only solid foundation we can give to the science itself must be laid on experience and observation."

Hume recognises that his re-thinking of human nature, based on scientific method, may not be to everyone's taste. He stresses the credit that will come to England by advancing the frontiers of philosophy and appeals for moderation by praising the English traditions of toleration and liberty. At this point we begin to understand that his arguments will be somewhat controversial.

In a footnote, Hume gives credit in the introduction to "some late philosophers in England", namely Locke, Shaftsbury, Mandeville, Hutchinson and Butler who have begun to "put the science of man on a new footing" but we begin to suspect that Hume's self-confidence will deliver us something more comprehensive and final.

To be continued.

What Happened Before the Big Bang? The New Philosophy of Cosmology

The Atlantic - What Happened Before the Big Bang? The New Philosophy of Cosmology

Last May, Stephen Hawking gave a talk at Google's Zeitgeist Conference in which he declared philosophy to be dead. In his book The Grand Design, Hawking went even further. "How can we understand the world in which we find ourselves? How does the universe behave? What is the nature of reality? Where did all this come from? Traditionally these were questions for philosophy, but philosophy is dead," Hawking wrote. "Philosophy has not kept up with modern developments in science, particularly physics."

Is philosophy "dead" or is Stephen Hawking wrong (again)?

What is philosophy Part 2

Not satisfied with the OED definition, let's take a look in the bible for looking-things-up pre the Internet era, Encylopædia Britannica.

The Ninth Edition of Britannia is a wonderful publication. Published in 1885, it contains articles written by some of the leading academics of the day. I was lucky enough to find a set in good condition at Barter Books in Alnwick in Northumberland many years ago.

Britannica has a five page article on the subject of philosophy. Consulting the List of Contributors in the Index we can see that the article was written by Andrew Seth MA, Professor of Logic at St Andrews University*
Extracts from EB:

• The meaning and scope of the term philosophy has varied considerably according to the usage of different authors and different ages
• Helpful introduction is to look at the historical use of the term in the history of Greek thought
• The tradition which assigns the first use of the word to Pythagorus "has hardly any claim to be regarded as authentic" [I love the use of language in old editions of Britannica]
• First used as a Greek verb by Herodotus and Thucydides, implying the pursuit of knowledge
• A specific sense of the word firsts meets us in Plato, who defines the philosopher as one who apprehends the essence or reality of things in opposition to the man who dwells in appearances and the shows of sense
• Logic, ethics, and physics, psychology, theory of knowledge, and metaphysics are all fused together by Plato in a semi-religious synthesis
• It is not until we come to Aristotle - the enclopædist of the ancient world - that we find a demarcation of the different philosophic disciplines, corresponding, in the main, to that still current [in 1885 that is]
• The earliest philosopher, or physiologers, had occupied themselves chiefly with what we may call cosmology; the one question which covers everything for them is that of the underlying substance of the world around them
• In Socrates and Plato, the start is made from a consideration of man's moral and intellectual activity; but knowledge and action are confused with one another, as in the Socratic doctrine that virtue is knowledge
• To this correspond the Platonic confusion of logic and ethics and the attempt to substitute a theory of concepts for a metaphysic of reality
• Aristotle separated the different aspects of reality here confounded, and became the founder of logic, psychology, ethics and æsthetics as separate sciences - while he prefixed to all enquiries the investigation of the ultimate nature of existence
• By the gradual sifting out of the special sciences, philosophy came to embrace primarily the inquiries grouped as "metaphysics" or "first philosophy" i.e. ontology proper (or the science of being as such) with its branch sciences of rational psychology, cosmology and (rational or natural) theology
• Subsidiary to metaphysics stand the sciences of logic and ethics, to which may be added æsthetics
• These are the three normative** sciences, which do not, primarily, describe facts, but rather prescribe ends
• It is with the ultimate synthesis that philosophy concerns itself, the sciences may be said to furnish philosophy with its matter, but philosophical criticism reacts upon the matter thus furnished, and transforms it

More from Britannica tomorrow, in particular delving further into the meaning of æsthetics

*According to the St Andrews University's website:
Andrew Seth Pringle-Pattison (1856-1931) was born in Edinburgh. He was professor of philosophy at University College, Cardiff (1883-87), and then professor of Logic and Metaphysics at St. Andrews (1887-91) and at Edinburgh (1891-1919). He added Pringle-Pattison to his name in 1898 to meet the conditions of a bequest. He was an influential teacher, and in his writings he examined philosophy through critical interpretations of the great philosophers. He wrote Scottish Philosophy: a comparison of the Scottish and German answers to Hume (1885), Hegelianism and Personality (1887), Man's Place in the Cosmos (1897), The Idea of God in the Light of Recent Philosophy (1917), The Idea of Immortality (1922), and Studies in the Philosophy of Religion (1930).

**In philosophy, normative statements affirm how things should or ought to be, how to value them, which things are good or bad, which actions are right or wrong. Normative is usually contrasted with positive (i.e. descriptive, explanatory, or constative) claims when describing types of theories, beliefs, or propositions. Positive statements are factual statements that attempt to describe reality. (from Wikipedia)

What is metaphysics?

I have just listened to Kit Fine in conversation with Nigel Warburton on the Philosophy Bites website on this very topic.

The key points are:

• the term was first used by an editor of Aristotle to describe a collection of his writing but it is not a term that Aristotle would have used. Metaphysics by Aristotle
• notoriously difficult to define
• meta means "beyond" or "after", but the term has a deeper meaning than "after physics"
• differs from scientific knowledge as metaphysical knowledge is "a priori", i.e. independent of observation / experience
• an example of a metaphysical issue in philosophy is the question of causation
• David Hume (1711-1776) held that we reason inductively by associating constantly conjoined events, and it is the mental act of association that is the basis of our concept of causation (this is now referred to as the Regularity Theory of Causation)
• An alternative view on causation is that there is some kind of necessary connection between one thing following another in the world
• The true nature of causation is not an empirical question, it cannot be proved scientifically, and hence it is a metaphysical issue
• Another example of a metaphysical question is the nature of a person
• What is a person - what is their very nature?
• Is a person a body, a soul, a combination of both or merely a collection of experiences?
• 'What is free will' and 'what is the nature of space and time' are other examples of questions that are metaphysical
• What is a number - are they the same as the signs for numbers (numerals), are they something abstract, existing in some form of Platonic realm independent of us, or are they a kind of mental construction akin to a fictional character made up by an author
• Metaphysics operates at a very general level and doesn't deal with specifics
• Metaphysics deals with the nature of things in themselves.
• There are similarities between mathematics and metaphysics in the use of a priori reasoning, but mathematics is a narrower subject
• In the 20th century, metaphysics came under attack, principally from the logical positivist movement
• For example AJ Ayer in Language Truth and Logic (1936) deployed the verification criterion of meaning to argue that metaphysical statements are meaningless
• It is only recently that metaphysics has recovered from these attacks and it is now flourishing