Is time travel into the past metaphysically possible

Is time travel into the past metaphysically possible

Philosophy Essay Advice: Make your writing as clear as you can. The ideal is to make it so clear that the reader requires no effort to understand it, and no misunderstanding is possible. You can’t be too clear. This is my number-one tip (along with answering the question–see below). Lack of clarity is the most common and the most serious flaw in student writing, and being clear is the most important thing you can do to improve it. The murkier your essay, the harder it will be for you to see whether it’s plausible, well argued, coherent, or relevant. Unclear writing is also a symptom of unclear thinking: if you have trouble saying something clearly, it’s usually because you don’t fully understand it. (This applies to professionals as well as students.) The ability to express difficult things clearly is one of the most valuable ‘transferable skills’ that a Philosophy degree can give you, and employers rate it highly.

Don’t make the essay too sophisticated or complex. Students have a natural tendency to try to run before they can walk. Slow down and be patient. It’s much better to make simple points well than complicated points badly.

Think for yourself, but don’t worry too much about whether you’re being original enough. No one expects undergraduates to come up with good ideas that they haven’t encountered in their reading or lectures (though it does happen!). There’s plenty of room for originality in stating familiar points in your own words. If you have got an original thought–something you haven’t heard in lectures or read about–be cautious. Make it as clear as you can. Don’t rely on it. Make sure your essay has other points in case your original idea turns out to be badly confused, or if the examiner can see that it’s obviously wrong. If you have serious doubts, leave it out- -or, better, discuss it with the lecturer before deciding.

Use plain English. Don’t use fancy words or complex sentence structures just for the sake of it. No one will be impressed. It will only make your essay harder to understand.

Illustrating an abstract point with a vivid example can help both you and the reader to understand it.

Don’t repeat yourself unnecessarily. Lengthy introductory or concluding paragraphs that merely repeat what you say elsewhere are worse than useless: they waste words and present an obstacle to the reader. Always ask yourself: will this introductory or concluding bit make it easier for the reader to understand the main body of the essay? If the answer is not obviously Yes, think again.

You don’t need a strong conclusion. You may find, on reflection, that the answer to the question set is not at all obvious–perhaps because the arguments on either side are about equal, or because there is more than one thing that the question can reasonably be taken to mean. In that case, this is the conclusion you should report. Say what you think the arguments show, even if you think it’s little or nothing, and explain why.

Unless you are a celebrity, your opinion counts for nothing. All that matters are the reasons you can give for it–reasons that readers can find forceful.

Other things equal, essays near the maximum word limit are better than those well below it. But don’t repeat yourself or say something irrelevant just to pad out the essay. And don’t exceed the word limit.




Answer the question–all parts of it. Better, make sure every part of the essay contributes towards answering it. Resist the temptation to go beyond the question. If you think you can answer the question in a single paragraph, you’ve gone wrong.

Many essay questions ask for a mixture of exposition and discussion: e.g. ‘State and evaluate X’s argument for the claim that P’. Don’t skimp on the exposition. Exposition is the foundation of your essay: get it wrong and everything else will be out of alignment. If the point to be discussed is not clear, you’re far more likely to stray from the topic and waste space with points not directly relevant. And you won’t know where to aim your critical discussion. The result is inevitably a rambling essay somewhere in the vicinity of the question set. It’s perfectly reasonable to use half the essay or more setting out the target, before making any critical remarks. The clearer you make the point to be discussed, the easier it will be to know what to say about it. A common mistake is to sketch the target only very roughly, in a paragraph. The result is usually that it’s hard to tell whether the objections hit the target. Students err far more often on the side of too little exposition than on the side of too much. Think of the old soldiers’ advice: Don’t shoot till you can see the whites of their eyes. (But expound only the claim or argument that you are going to write about.)

Don’t try to squeeze too much in. It’s far better to make fewer points in depth than more points superficially.

Use technical or contested terms only if there’s a strong reason for it. And be sure to explain what you mean by them. This includes any term that could mean different things in the context, or whose meaning is not clear to the general public: e.g. ‘foundationalism’, ‘substance’, ‘dualism’, ‘materialism’, ‘rationalism’ ‘supervenience’, ‘self’. Say as much about their meaning as the reader needs in order to understand the essay, and no more. If you’re unsure whether you need to explain a term, try to recall whether your lecturer explained it. If so, do likewise. (And be sure you get it right!)

Proofread your essay carefully. Don’t just use a spellchecker. Make an effort to get the grammar and punctuation exactly right, just as you would if you were writing a job application. If need be, get a friend to check it.

Reading List:

  1. Introduction: The nature of metaphysics
  2. W. Hamlyn, Metaphysics (CUP 1984), Introduction.
    M. Loux, Metaphysics (Routledge 1998), Introduction.
    E. J. Lowe, A Survey of Metaphysics (OUP 2002), Introduction.
    G. Schlesinger, Metaphysics (Blackwell 1983), ch. 1.
    P. van Inwagen, Metaphysics, Stanford Encyclopedia of Philosophy 2008.


  1. Do we have a soul?

Dualism and materialism

  1. Olson, Why I don’t believe in souls, §§1-5. (on Blackboard)
    R. Swinburne, The Evolution of the Soul (2e, OUP 1997), Introduction (pp. 1-16).
    P. van Inwagen, Metaphysics (4e, Westview 2014), pp. 223-230.
  2. Hawthorne, Cartesian dualism, in P. van Inwagen and D. Zimmerman, eds., Persons: Human and Divine (OUP 2007), 87-98.
  3. Taylor, Metaphysics, 4e (Prentice Hall 1992), ch. 2.



  1. Olson, Why I don’t believe in souls, §6.
    A. Segal, A sane soul-hypothesis and the sane materialist alternative, §2
    E. Olson, The appearance and the evidence, §1.
    D. Bell, Husserl (Routledge 1990), ‘Conscious bodies’, pp. 162-168 (208-214 in the print


Traditional arguments for dualism

  1. Plantinga, Materialism and Christian belief, in P. van Inwagen and D. Zimmerman , eds., Persons: Human and Divine (OUP 2007), Part 1 (pp. 99-118)
  2. van Inwagen, Metaphysics, pp. 230-245.
    E. Olson, Why I don’t believe in souls, §§7, 8
    A. Segal, A sane soul-hypothesis and the sane materialist alternative, §§5-7. J. Foster, The Immaterial Self (Routledge 1991), pp. 202-212.
  3. Swinburne, The Evolution of the Soul, ch. 8.
    B. Williams, Descartes (Penguin 1978), ch. 4.
    D. Zimmerman, Two Cartesian arguments for the simplicity of the soul. American

Philosophical Quarterly 28 (1991): 217-226.


New arguments for dualism:

  1. Segal, Why I believe I am a soul, §§8-17.
    E. Olson, Fuzzy edges and amputations.

    A. Segal, Materialism is metaphysically messy or morally absurd. E. Olson, The Paradox of Increase. Monist 89 (2006): 390-417.

  2. van Inwagen, Material Beings (Cornell 1990), §§2, 3, 8, 9.


Arguments for materialism

  1. Olson, Why I don’t believe in souls, §§10-16.
    A. Segal, A sane soul-hypothesis and the sane materialist alternative, §§3-8
    further reading
    D. Braddon-Mitchell and F. Jackson, Philosophy of Mind and Cognition, 2e (Blackwell 2007), ch. 1.
    P. van Inwagen, Metaphysics, pp. 260-265.
    P. Smith and O. R. Jones, The Philosophy of Mind (CUP 1986), ch. 4, ‘Difficulties for

the dualist’.
C. McGinn, The Character of Mind, 2e (OUP 1997), ch. 2, ‘Mind and body’.
E. J. Lowe, An Introduction to the Philosophy of Mind (CUP 2000), ch. 2, ‘Minds, bodies

and people’.
R. Taylor, Metaphysics, 4e (Prentice Hall, 1992), chh. 2-4.



  1. Time

Time’s Passage
Olson, The passage of time, in R. LePoidevin, et al., eds., Routledge Companion to

Metaphysics (Routledge 2009). Available at

van Inwagen, Metaphysics, 4e, ch 4, Temporality, pp. 71-81.


  1. Dyke. 2011. Metaphysics of time. Routledge Encyclopedia of Philosophy.
    R. LePoidevin. 2003. Travels in Four Dimensions (OUP 2003), ch. 8, Does Time Pass? A. N. Prior, Changes in events and changes in things, in his Papers on Time and Tense

(OUP 1968), repr. in LePoidevin and M. MacBeath, eds., The Philosophy of Time

(OUP 1993)
K. Seddon, Time: A Philosophical Treatment (Croom Helm 1987), 3-25.


Objections to the dynamic view

  1. M. E. McTaggart, The unreality of time, in R. Le Poidevin and M. MacBeath, eds., The Philosophy of Time, OUP 1993, 23-34 (original work 1927). Also reprinted as ‘Time: an excerpt from The Nature of Existence’ in P. van Inwagen and D. Zimmerman, eds., Metaphysics: The Big Questions, 2e, Blackwell 2008.

van Inwagen, Metaphysics, ch 4, pp. 81-106.
Craig Bourne, When am I?, Australasian Journal of Philosophy 80 (2002).

Olson, The Rate of Time’s Passage, Analysis 2009.
G. Schlesinger, Aspects of Time (Hackett 1980), ch. 3. Seddon, Time, 44-70.



  1. Taylor, Fate (ch. 6 of Metaphysics, 4e, Prentice Hall 1992, 54-67).

van Inwagen, An Essay on Free Will (OUP 1983), ch. 2, Fate.

  1. Ryle, It was to be, in his Dilemmas (CUP 1954)
    Seddon, Time, 105-133.
    van Inwagen, What does an omniscient being know about the future? In J. Kvanvig,

ed., Oxford Studies in the Philosophy of Religion 1, OUP 2008, available at <>.

Thank goodness that’s over! essential reading
A. N. Prior, Thank goodness that’s over, Philosophy 34, 1959, 12-17. Available online

via library catalogue.
D. H. Mellor, Real Time II (Routledge 1998), sections 4.1-4.2 (39-42).

  1. Hare, Time–Emotional asymmetry. In H. Dyke and A. Bardon, eds., A Companion

to the Philosophy of Time, Wiley 2013. Schlesinger, Aspects of Time, ch. 2 Seddon, Time, 26-43.


The appearance of time’s passage
P. Horwich, Our sense of passage (§2.6 of Asymmetries in Time, MIT Press 1987,

Mellor, Real Time II, §§1.1-1.3 (pp. 7-11), 2.1-3.2 (19-32).


Time travel:

  1. Lewis, The paradoxes of time travel, American Philosophical Quarterly 13 (1976): 145-152.
  2. J. Lowe, A Survey of Metaphysics, OUP 2002, ch. 18.
    D. H. Mellor, Real Time II, ch. 12
    van Inwagen, Changing the past, Oxford Studies in Metaphysics 5 (2010).

Available at  <>.