Jon asked

You replace a defective part in your car. The next day you do the same thing with another part and then do so each day until you have replaced every part with a new one. Is what you have at the end of this process the same car with new parts or is it a new car? And if it is different when did it become so?

Answer by Craig Skinner

You raise a classical question as to how much compositional change (if any) an entity can undergo and still remain (numerically) the same entity. First raised by Plutarch as the repeatedly-repaired Ship of Theseus.

We could say that any change whatever destroys a thing’s identity (so called Mereological Constancy). Identity requires the selfsame atoms, none added, none taken away. So the new car exiting the showroom is already not the same car that sat there a moment ago — some of the tyre atoms have transferred to the floor, some new carbon atoms from the fuel are now part of the cylinder linings etc. As for people, you couldn’t shake hands with the same person twice. On this view, what we normally think of as an entity such as a car or a person, is really a vast series of fleeting different entities.

But we generally allow that things can change their parts without loss of identity eg I now wish to say I am the same man (now receiving a pension) as the young fellow who contributed to that pension from his wages years ago, and he saved because he thought the old boy who would benefit one day would be him, even though I am composed of completely different atoms from the me of 40 years ago. And similarly with artefacts such as cars or houses.

If we allow any part replacement at all, we are logically compelled to allow complete replacement of parts. This is because of the transitivity of identity (if A is identical with B, and B is identical with C, then A is identical with C) so that if its the same car after the oil filter is changed, it’s the same car after a tyre is later changed etc etc right up to complete replacement of parts. So, in short, the car at the end of the process you describe is the same car, as I am the same man at the end of my life.

However Thomas Hobbes (using the ship of Theseus example) pointed out a problem that arises if the old parts, instead of being binned, are kept, and then, when all the parts which constituted the original car are available, they are reconstructed into a car. Now we have 2 cars, let’s call them “Renovated” (Reno) which I have been driving all along, and “Reconstructed” (Reco) which has been built from the heap of spare parts accumulated over the years. Which car is to be identified with the original car?

There is something to be said for each option.
In favour of Reno: we routinely allow parts replacement; if the old parts had been discarded, we would have accepted Reno as a matter of course; and it’s the car I’ve been driving, taxing and fuelling all along.
In favour of Reco: if the original car had been disassembled/reassembled we would have accepted it as the same car as a matter of course; and, after all, Reco has all and only the parts of the original.

Possible solutions:

1. Both cars are the original. But this entails either one thing being in two places at once (not plausible) or that the original car was really two things which gradually separated (problematic – on seeing a single object, are we seeing one or two, or three or more, different things?)

2. Reno is the same car. Reco comes into existence only when assembled from old parts. Until then, these parts don’t belong to any car. If no renovation had occurred, these parts would have still belonged to the original car and we would have had one car throughout, initially assembled, later part-disassembled, later fully disassembled, finally reassembled. But a part cant belong to 2 cars at once. If my car’s oil filter is removed, it is still part of my (slightly disassembled) car, but once a replacement filter is fitted, the old one is no longer part of my car (or any other) although it might be reconditioned and become part of another car in the future – even one made of all and only the former parts of my car.

I prefer 2. to 1.

Answer by Shaun Williamson

It really doesn’t matter. Not every question has a definite or sensible answer.

Language was invented by human beings so that they could talk to each other about the things that interest them. It is as precise or as imprecise as we want it to be.

Ray asked:

What does it mean to say that there are no definitive answers to philosophical questions and why might this be a good thing?

How do philosophers decide which answers are worth considering?

Answer by Tony Fahey

The first thing that has to be said in response to the first of the above questions is that it points to a paradox, that is, in arguing, as certain philosophers do, that there are no definitive answers to philosophical questions, one is making a definitive, and thus contradictory, statement. However, whilst I acknowledge the anomaly in this remark, I would defend it by arguing that although, at certain times, in their search for truth, philosophers appear to attach themselves to, what appear to be, incontrovertible truths, ultimately, following what Karl Popper calls ‘the law of falsification’, they accept that, given further evidence, they may have to concede that that which they have heretofore held as valid is in fact no longer sustainable. (We should remember that history is replete with examples which support this view, not the least of them being, of course, evidence that showed that our world is not flat, and that our planet is not the centre of the universe.)

Thus, it can be said that it is a good thing to hold that there are no such things as definitive answers, because it means that philosophy is (or should be) always open to the view that its theories, ideas, beliefs, and/ or worldviews may be have been built on sand.

How do Philosophers decide which answers are worth considering?

With regard to Ray’s second question, firstly, let me say that if I am to respond to this question directly, I would say that the answers that philosophers decide are worth considering are those that deal with questions such as: Who am I? Why is there something rather than nothing? Is there a God? Is the mind, at birth, a blank slate? Are there such things as innate ideas or concepts? Are there limitations to human understanding? How ought one behave? Are there really such things as inalienable rights? What is truth? What is beauty? Which is the most convincing argument for the creation of the universe: Creationism or the ‘Big Bang’? What is the purpose of human existence?, and so on.

However, it seems to me that rather than asking which answers are worth considering, what really is at issue here is which questions do philosophers consider worth answering. Given that this is the case, I would say that it should be remembered that philosophy is concerned primarily with a search for wisdom and a love of truth. Thus, any question worth answering from a philosophical point of view would have to fall under this particular rubric. And falling under this rubric we find such categories as epistemology (the theory of knowledge; the branch of philosophy that inquires into the nature and possibility of knowledge: what can we know?); ethics (the branch of philosophy concerned with codes of behaviour, the study of the moral value of human conduct: how ought one behave?); aesthetics (the branch of philosophy concerned with the study of the concepts of beauty and taste: what is beauty?); logic (the branch of philosophy that analyses the patterns of reasoning), and metaphysics (an inquiry into that which comes after physics, or what lies beyond nature).

Solomon asked:

Why are most philosophical works linguistic or syntactic today?

Do you think that ontology has finished and is logically impossible?

Answer by Shaun Williamson

Well I don’t think they are, it really depends on which country you are in. Are you in the U.S.A. where W.V.O. Quine holds sway? Are you in Great Britain where the Empiricists prevail? Are you in Germany which is split in two. In the North the Romantic tradition which includes Nietzsche and Heidegger prevails. In the South the Analytic tradition inherited from the British and French empiricists prevails.

The southern German tradition emigrated to the U.S.A. in the 1930s to escape Hitler and displaced the native U.S. tradition, replacing it with logical positivism and W.V.O. Quine.

However philosophy is about truth, not about fashion or about trends. So you should not concern yourself with what the majority of philosophical works say. Publishing follows trends, philosophy is about truth.

Madelene asked:

Is psychology a pseudo-science?

Answer by David Robjant

What a charming question. But what is proper science?

There is a trend in all areas of research these days, be they science, pseudo-science or mere humanities, to chase research funding by undertaking to find, and then finding, some positive result. Few researchers these days are tenured professors free to disport themselves picking holes in anybody else’s well funded research. Academics these days are too busy chasing the money. This introduces an incentive across all areas of research to sit on any negative results for years – or possibly forever. And in such an academic environment a real question arises about the extent to which even Chemistry can be said to remain a hard science, if the ordinary motive of enquiry is under threat. It was that motive which previously drove the publication of evidence showing the error of some theory, and it was the threat of such evidence that made those theories scientific in the first place.

The issue is not merely that researchers in the sciences and the humanities are now professionals. I do not glorify the various golden ages in which a larger proportion were moneyed amateurs – those ages are glorious enough already, and there have also been quite different kinds of golden age in the sciences, under the ignoble pressures of War, for instance – where the motive of enquiry met the motive of national survival. No, the issue is the way in which the ‘performance’ is now quantified.

Unlike in the second world war, there is presently an assumption, based on wildly counter-empirical craziness like Public Choice Theory and Game Theory now disowned by John Forbes Nash, that researchers are lazy galley slaves interested only in the prospect of a sinecure. Unless goaded by regular ‘assessments’ and ‘sanctions’, the researcher in the sciences or the humanities ‘must’ be bound to sit on his arse and play battleship all day, as no doubt, before such sound financial measures were introduced, did such layabouts as Einstein and Socrates. But to treat a researcher as a galley slave, whether out of concern for the efficient use of public resources or simply out of hatred of anyone with obscure satisfactions, is automatically to corrode his original motivating curiosity and move his area of competence towards tax-accountancy.

Our over-assessed system of research is now selecting for men and women who can efficiently game that system, with more of an eye on the journal rankings and Leverhulme guidelines than on the Good. You might say, ‘Grow up, this is reality.’ But it has become a reality on the basis of an empirically false theory of human motivation, in pursuit of an efficiency which is wholly chimerical, and the only positive result has been to dis-incentivise the kind of whistle-blowing publication upon which all advances in the sciences and the humanities must depend.

Is psychology a pseudo-science? Well, not more than other sciences and humanities in which the systems of funding have come to dominate the lives of their beneficiaries.

Martin asked:

If the Big Bang was a reality, where exactly did it happen?

We are led to believe that the Big Bang took place between 10 and 20 billion years ago a humungous explosion at a point in the universe, resulting in the expanding state that we recognise today. For this to be true there must be an ever increasing ‘dead zone’ centered around the point where the Big Bang took place, void of everything as all the exploding arisings race away from the original point so this would mean the universe is hollow and have we found the dead zone?

Answer by Stuart Burns

You are confusing an ‘explosion of space’ with an ‘explosion in space’. In the latter, your expectation of a ‘dead-zone’ at the center is apt. In the former, it is not.

The explosion did not take place ‘at a point in the universe’. The explosion took place at a point which was the universe. Where exactly did this happen? Well, you can consider that it took place at a point between your ears. All of space (the entire universe) expanded uniformly from that singularity point. All of space (the entire universe) is still expanding uniformly from that singularity point. The uniform nature of this expansion means that each and every point in the universe was the center of that explosion, and remains the center of that expansion the point between your ears, the point between my ears, and the center of some far away galaxy. The explosion did not involve ‘exploding arisings’ that are racing away from the center. The explosion involved space itself. Each and every point of space is racing away from every other point.

Kristy asked:

How do you think philosophical questions fit into a consideration of modern life?

Answer by Shaun Williamson

I don’t think they fit in at all. Philosophy has nothing to teach us about how to lead our lives. It has nothing to teach us about morality. There are no philosophical truths. The problem is of course that unless you study philosophy you will never be able to decide that what I say is true or if it is false.

Philosophical questions are just the result of mental confusions but it is natural to humans to be in a state of confusion and to want to resolve that confusion.

As Wittgenstein said ‘Philosophy is a battle against the bewitchment of our intelligence by means of our own language’.