International Conference

Deep Disagreements
Philosophical and Legal Perspectives

New York University
Department of Philosophy, 5 Washington Place, Seminar Room 202
October 6–7, 2017

Attendance is free, but space is limited. Please register here.
Scientific Organization: Paul Boghossian, Geert Keil, Ralf Poscher
If you have any question, contact Amy Moore (

People are frequently at odds over issues that equally concern them. Many disagreements that are central to political, social, ideological or religious conflicts are deep in the sense that they can neither be resolved through a compelling argument nor by gathering further information, nor do they arise from readily discernible misunderstandings.
The phenomenon of deep disagreement raises issues for many areas, especially within philosophy and law. Deep disagreements often have an extremely complex structure, in which different sources of disagreement intersect and in which it is difficult to trace the real source of dissent.
Epistemological aspects of disagreements have been tackled in the philosophical debate on peer disagreement, which focuses on the question of whether or not it is rational to stick to one’s belief if someone of equal competence and well-informedness holds a contrary one.
In legal theory, the debate about the right answer thesis centers around the question whether all legal disputes have a single right answer. If we do not presuppose a right answer, Ronald Dworkin’s famous argument of the semantic sting seems to force us into an implausible conclusion: that disagreements in law are merely based on linguistic misunderstandings and that it cannot be explained what we argue about in law.
One advantage of focusing on legal disagreements in so-called hard cases is that these come with built-in social significance. Supreme Court split verdicts are of particular interest: There is much at stake, they are based on elaborate argumentation, and they constitute disagreements among peers.


Friday, October 6, 2017

09:30 – 09:40
Paul Boghossian (NYU)

09:40 – 10:00
Geert Keil (HU Berlin)
Ralf Poscher (Freiburg University)

10:00 – 11:15
Jennifer Lackey (Northwestern University)
Experts and Disagreement

11:30 – 12:45
Daniel Viehoff (NYU)
Authority and Disagreement

Lunch Break

14:30 – 15:45
Liam Murphy (NYU)
Deep Disagreement: Comparing Law and Morality

16:00 – 17:15
Michele Moody-Adams (Columbia)
Constructive Disagreement: A Prelude

17:30 – 18:45
Philipp Pettit (Princeton)
Disagreements in Conceptual Choice, not Conceptual Analysis

Conference Dinner

Saturday, October 7, 2017

09:30 – 10:45
Matthias Kumm (NYU)
Deep Disagreement and Political Institutions

11:00 – 12:15
Jeremy Waldron (NYU)
Deep Disagreement and Civility

12:30 – 13:45
Isabell Villanueva (HU Berlin)
To the Nines: Finding the Perfect Peer

Lunch Break

15:30 – 16:45
Ralf Poscher (Freiburg University)
Legal Disagreements in Hard Cases

17:00 – 18:15
Joseph Raz (Columbia)
Responding to Disagreement

  • In cooperation with Kiel University