In the theory of

empirical knowledge Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...

, the problem of the speckled hen is whether a single immediate

observation Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the perception and recording of data via the use of scientific instruments. The ...

of a speckled

hen Hen commonly refers to a female animal: a female chicken, other gallinaceous bird, any type of bird in general, or a lobster. It is also a slang term for a woman. Hen or Hens may also refer to: Places Norway *Hen, Buskerud, a village in Ringer ...

provides a certain knowledge of the number of speckles observed. Clearly, this is not an isolated example, and therefore it is of fundamental nature.

Roderick Chisholm Roderick Milton Chisholm (; November 27, 1916 – January 19, 1999) was an American philosopher known for his work on epistemology, metaphysics, free will, value theory, and the philosophy of perception. The ''Stanford Encyclopedia of Philosophy ...

, "The Problem of the Speckled Hen", ''Mind'' 51 (1942): pp. 368–373. Philosophically, this problem probes the limits of

knowledge by acquaintance In philosophy, a distinction is often made between two different kinds of knowledge: knowledge by acquaintance and knowledge by description. Whereas knowledge by description is something like ordinary propositional knowledge (e.g. "I know that ...

: one is unable to know with

certainty Certainty (also known as epistemic certainty or objective certainty) is the epistemic property of beliefs which a person has no rational grounds for doubting. One standard way of defining epistemic certainty is that a belief is certain if and ...

the existence of determinate things in one's experience merely by the virtue of the experience.

attributes it to

Gilbert Ryle Gilbert Ryle (19 August 1900 – 6 October 1976) was a British philosopher, principally known for his critique of Cartesian dualism, for which he coined the phrase "ghost in the machine." He was a representative of the generation of British ord ...

suggesting to

A. J. Ayer Sir Alfred Jules "Freddie" Ayer (; 29 October 1910 – 27 June 1989), usually cited as A. J. Ayer, was an English philosopher known for his promotion of logical positivism, particularly in his books '' Language, Truth, and Logic'' (1936) ...

. It is viewed as a criticism of the view expressed by

C. I. Lewis Clarence Irving Lewis (April 12, 1883 – February 3, 1964), usually cited as C. I. Lewis, was an American academic philosopher. He is considered the progenitor of modern modal logic and the founder of conceptual pragmatism. First a noted logici ...

that there can never be "positive bafflement in the presence of the immediate, because there is here no question which fails to find an answer".C. I. Lewis, Mind and the World-Order, p. 128, As cited by Chisholm (1942).

Joseph Heath Joseph Heath (born 1967) is a Canadian philosopher. He is professor of philosophy at the University of Toronto, where he was formerly the director of the '' Centre for Ethics''. He also teaches at the School of Public Policy and Governance. He ...

remarks that this problem is one of the "descendants of Descartes's '

chiliagon In geometry, a chiliagon () or 1000-gon is a polygon with 1,000 sides. Philosophers commonly refer to chiliagons to illustrate ideas about the nature and workings of thought, meaning, and mental representation. Regular chiliagon A '' regular c ...

' argument in the sixth of his ''

Meditations ''Meditations'' () is a series of personal writings by Marcus Aurelius, Roman Emperor from AD 161 to 180, recording his private notes to himself and ideas on Stoic philosophy. Marcus Aurelius wrote the 12 books of the ''Meditations'' in Koine ...

''".

, ''Following the Rules: Practical Reasoning and Deontic Constraint'', Oxford: OUP, 2008, p. 305, note 15). A. J. Ayer suggested that if we are unable to enumerate speckles accurately, then it is incorrect to suggest that the "sense-data" provides a definite number of speckles despite the fact that the hen does have a definite number of them, clearly outlined. In Ayers' words, speckles are enumerable only if in fact they have been enumerated. A number of philosophers analyzed the merits of this proposition. Chisholm concludes that the problem of the speckled hen emphasizes the fact that there are basic propositions (

synthetic proposition Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic o ...

s which do not refer beyond the content of the immediate experience) that are necessarily imprecise.

References

Epistemology of science Evidence Observation Philosophy of science {{science-philo-stub