Justification and Probability
Lead Research Organisation:
University of Glasgow
Department Name: School of Humanities
Abstract
Under what conditions are we justified in believing something? A very simple and natural answer to this question is that we are justified in believing something when it is sufficiently likely to be true. Managing one's beleiefs in a reasonable and responsible manner is all about minimising the risk of error. As simple and natural as this answer seems, however, I believe it to be mistaken.
Suppose that 100 people attended a concert but we know that only one ticket was ever sold. As such, we know that only one of the people at the concert attended legitimately and the other 99 were gatecrashers. Suppose we know that Joe was one of the people who attended the concert but have no further information about him. Clearly, in light of our evidence, it's very likely that Joe was a gatecrasher. But should I really draw the conclusion that Joe was a gatecrasher and treat him accordingly? Should I go about asserting that Joe was a gatecrasher - should I inform his friends, his family, his employer for instance? Should Joe be arrested and convicted and appropriate punishment applied to him? Most of us would agree that this would be exceedingly unfair and, under prevailing legal practice, statistical evidence of this kind would not be deemed a legitimate basis for a conviction.
But if I'm not justified in believing that Joe was a gatecrasher, then justification is not simply a matter of likelihood after all - there must be more to it than this. Interestingly, if an eye-witness claimed that she saw Joe scaling the fence to get into the concert then we would generally have no qualms about believing that Joe was a gatecrasher and acting accordingly - and such evidence could well be deemed a legitimate basis for conviction in a court. And yet, we're all aware that testimony is fallible - the eye-witness could be lying or mistaken. Indeed the probability that Joe was a gatecrasher given that a witness testified that she saw him scaling a fence is plausibly not as high as 99%.
My primary aim in this project is to try and get to the bottom of this puzzle and, in so doing, come to a new understanding of what it takes to be justified in believing something. The research is relevant not just to epistemologists and academic philosophers but to anyone who has wondered what to believe about a given topic or how to evaluate a given piece of evidence. As the above example suggests, the research also has a bearing on questions about how best to understand and rationalise our legal practices. I aim to publish the results of this research in a monograph and a research paper. The research will be conducted primarily in Scotland and in collaboration with a number of philosophers working throughout Scotland. Scotland, at present, boasts a number of high profile philosophy departments and research centres with particular strength in epistemology.
Suppose that 100 people attended a concert but we know that only one ticket was ever sold. As such, we know that only one of the people at the concert attended legitimately and the other 99 were gatecrashers. Suppose we know that Joe was one of the people who attended the concert but have no further information about him. Clearly, in light of our evidence, it's very likely that Joe was a gatecrasher. But should I really draw the conclusion that Joe was a gatecrasher and treat him accordingly? Should I go about asserting that Joe was a gatecrasher - should I inform his friends, his family, his employer for instance? Should Joe be arrested and convicted and appropriate punishment applied to him? Most of us would agree that this would be exceedingly unfair and, under prevailing legal practice, statistical evidence of this kind would not be deemed a legitimate basis for a conviction.
But if I'm not justified in believing that Joe was a gatecrasher, then justification is not simply a matter of likelihood after all - there must be more to it than this. Interestingly, if an eye-witness claimed that she saw Joe scaling the fence to get into the concert then we would generally have no qualms about believing that Joe was a gatecrasher and acting accordingly - and such evidence could well be deemed a legitimate basis for conviction in a court. And yet, we're all aware that testimony is fallible - the eye-witness could be lying or mistaken. Indeed the probability that Joe was a gatecrasher given that a witness testified that she saw him scaling a fence is plausibly not as high as 99%.
My primary aim in this project is to try and get to the bottom of this puzzle and, in so doing, come to a new understanding of what it takes to be justified in believing something. The research is relevant not just to epistemologists and academic philosophers but to anyone who has wondered what to believe about a given topic or how to evaluate a given piece of evidence. As the above example suggests, the research also has a bearing on questions about how best to understand and rationalise our legal practices. I aim to publish the results of this research in a monograph and a research paper. The research will be conducted primarily in Scotland and in collaboration with a number of philosophers working throughout Scotland. Scotland, at present, boasts a number of high profile philosophy departments and research centres with particular strength in epistemology.
Planned Impact
During the course of this fellowship, I will bring the results of my research to two key audiences outside of the Higher Educatiuon sector - legal professionals and members of the general public with an interest in fundamental philosophical questions. I will accomplish this through the organisation and delivery of two targeted events - an international conference for philosophers, legal theorists and legal professionals and a widely advertised public lecture.
The research undertaken in this project will have a direct bearing on a pressing question about the propriety of a certain aspect of actual legal practice - namely, the tendency to play down the significance of statistical evidence when compared with evidence of other kinds. The research undertaken in this project offers an original way of approaching this question. In December 2014 I will co-organise an international conference on statistical evidence in the law at which I will present my research. The conference will take place at the University of Glasgow and will be aimed at philosophers, legal theorists and legal professionals. A number of philosophers, legal theorists and legal professionals have already expressed an interest in attending or presenting at this conference. I have organised two very successful international conferences in the past - in December 2009 and May 2010.
The research undertaken in this project will also have a direct bearing on a number of very central, well known philosophical questions and quandaries, particularly questions about what we are justified or rational in believing about the world. There is widespread interest in fundamental philosophical questions amongst the general public, with works of popular philosophy regularly featuring on bestseller lists. The research undertaken in this project offers a novel perspective on fundamental questions about justification and rationality, which I will outline and defend in at least one widely advertised public lecture to take place in Glasgow in January 2015. I have delivered public lectures in the past on topics germane to this research project - such as 'God and the External World' presented at the University of Glasgow in March, 2009, which was well attended by members of the general public.
The research undertaken in this project will have a direct bearing on a pressing question about the propriety of a certain aspect of actual legal practice - namely, the tendency to play down the significance of statistical evidence when compared with evidence of other kinds. The research undertaken in this project offers an original way of approaching this question. In December 2014 I will co-organise an international conference on statistical evidence in the law at which I will present my research. The conference will take place at the University of Glasgow and will be aimed at philosophers, legal theorists and legal professionals. A number of philosophers, legal theorists and legal professionals have already expressed an interest in attending or presenting at this conference. I have organised two very successful international conferences in the past - in December 2009 and May 2010.
The research undertaken in this project will also have a direct bearing on a number of very central, well known philosophical questions and quandaries, particularly questions about what we are justified or rational in believing about the world. There is widespread interest in fundamental philosophical questions amongst the general public, with works of popular philosophy regularly featuring on bestseller lists. The research undertaken in this project offers a novel perspective on fundamental questions about justification and rationality, which I will outline and defend in at least one widely advertised public lecture to take place in Glasgow in January 2015. I have delivered public lectures in the past on topics germane to this research project - such as 'God and the External World' presented at the University of Glasgow in March, 2009, which was well attended by members of the general public.
People |
ORCID iD |
| Martin Smith (Principal Investigator / Fellow) |
Publications
M Smith
(2016)
Between Probability and Certainty: What Justifies Belief
Smith M
(2018)
When Does Evidence Suffice for Conviction?
in Mind
Smith M
(2018)
The logic of epistemic justification.
in Synthese
Smith M
(2020)
Coin trials
in Canadian Journal of Philosophy
Smith M
(2021)
Civil liability and the 50%+ standard of proof
in The International Journal of Evidence & Proof
Smith M
(2021)
More on Normic Support and the Criminal Standard of Proof
in Mind
Smith, M.
(2020)
The Hardest Paradox for Closure
in Erkenntnis
| Description | The question of what we should believe about the world, given our limited evidence and information, is one of the central problems in epistemology - and a question that we all face in various forms each day of our lives. According to one very common picture, we are justified in believing a proposition when our evidence makes it sufficiently *probable* - sufficiently likely to be true. On this way of thinking, forming justified beliefs is a matter of minimising the chance of error and maximising the chance of truth. In this project I drew attention to new and different kind of relation that evidence can bear to propositions - a relation that is completely separate from probability. Say that a piece of evidence E *normically supports* a proposition P just in case the situation in which E is true and P is false is less normal, in the sense of requiring more explanation, than the situation in which E and P are both true. I showed that this approach to justified belief offered surprising solutions to a number of long standing puzzles in epistemology and in legal theory, such as the lottery and preface paradoxes and the paradox of the gatecrasher. I also developed a detailed formal, mathematical model of normic support and contrasted its formal properties with those of probability. I argued that the formal features of normic support are able to shed new light on aspects of human reasoning that are very puzzling from a probabilistic perspective. Thinking about justification in terms of normic support, rather than probability, ultimately guides us to a new way of looking at uncertainty and of managing human fallibility. I set out these ideas in a monograph which was published by Oxford University Press in January 2016. I explore some of the legal applications of my theory in a paper that has recently been published in the journal Mind. |
| Exploitation Route | My findings bear directly on a number of central questions and problems in philosophy and should be of considerable interest to contemporary philosophers. The theory that I have developed also has broader implications - for the psychology of human reasoning and also for legal theory. In psychology, the theory offers a new perspective on certain pervasive patterns of human reasoning that have been widely regarded as irrational. In legal theory, my view has a direct bearing on how we should understand different legal standards of proof, and how we should treat statistical evidence in legal cases. |
| Sectors | Government, Democracy and Justice |
| Description | Conference on statistical evidence in epistemology and the law |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | As part of the Justification and Probability research project, I organised a major international conference in Glasgow in December 2014 on statistical evidence in epistemology and the law. At this conference I presented project research and outlined a number of applications to legal standards of proof, jury instructions and legal drafting. Other presentations were given by philosophers, legal theorists and practising lawyers from the UK, Europe, Asia and North America. The event was attended by over 30 academics, postgraduate students, undergraduate students and legal professionals. This event lead to the development of a network of philosophers and legal theorists in universities throughout Scotland and we are currently applying for funding to support further events of this kind. |
| Year(s) Of Engagement Activity | 2014 |
| URL | http://www.serpn.philipebert.info/events/index.html |