Why Knowledge Should Not Be Typed: An Argument against the
Type Solution to the Knowability Paradox
by
MASSIMILIANO CARRARA
Department of Philosophy, University of Padua
and
DAVIDE FASSIO
Department of Philosophy, University of Geneva
Abstract: The Knowability Paradox is a logical argument to the effect that, if there are truths not
actually known, then there are unknowable truths. Recently,Alexander Paseau and Bernard Linsky
have independently suggested a possible way to counter this argument by typing knowledge. In this
article, we argue against their proposal that if one abstracts from other possible independent
considerations supporting reasons for typing knowledge and considers the motivation for a type-
theoretic approach with respect to the Knowability Paradox alone, there is no substantive philo-
sophical motivation to type knowledge, except that of solving the paradox. Every attempt to
independently justify the typing of knowledge is doomed to failure.
Keywords: Knowability Paradox, type theory, epistemic paradoxes
1. Introduction
A LOGICAL ARGUMENT known as the Knowability Paradox starts from the assump-
tion that every truth is knowable and leads to the consequence that every truth is
also actually known. Given the ordinary fact that some true propositions are not
actually known, the argument then concludes, by modus tollens, that there are
unknowable truths.
The straightforward conclusion of the argument seems to be seriously problem-
atic for those assuming that every truth is, at least in principle, knowable. For
instance, it is problematic for some semantic anti-realist theories that require an
epistemic characterization of the notion of truth and certain “optimistic” views in
epistemology and philosophy of science, according to which no truths exceed our
cognitive capacities to grasp them.
1
Many strategies have been suggested in order to avoid the paradoxical conclu-
sion.
2
Recently, Alexander Paseau (2008) and Bernard Linsky (2009) have inde-
1 An example of this view is the so-called “Gödelian Optimism”.
2 For an introduction and a general overview of the various critical approaches to the paradox, see
Brogaard and Salerno (2009) and Kvanvig (2006).
THEORIA, 2011, 77, 180–193
doi:10.1111/j.1755-2567.2011.01100.x
© 2011 Stiftelsen Theoria. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK,
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