The linguistic principle that any thought a person can have "can be expressed by some sentence in any natural language," and that anything which can be expressed in one language can also be expressed in another.
See also:
Etymology:
Proposed by philosopher Jerrold Katz in "Effability and Translation" (1978)Examples and Observations:
- "Many authors advocate a principle of effability, according to which a natural language
can express anything that can be thought. A natural language is
supposedly capable of rendering the totality of our experience--mental
or physical--and, consequently, able to express all our sensations,
perceptions, abstractions up to the question of why is there Something
instead of Nothing. It is true that no purely verbal language ever
entirely achieves total effability: think of having to describe, in
words alone, the smell of rosemary. We are always required to supplement
language with ostentions, expressive gestures, and so-called 'tonemic'
features. Nevertheless, of all semiotic
systems, nothing rivals language in its effability. This is why almost
all projects for a perfect language start with natural, verbal languages
as their model."
(Umberto Eco, The Search for the Perfect Language. Wiley, 1995) - "According to [Jerrold Katz], for every thinkable thought there is,
in every language, a sentence one of whose senses uniquely corresponds
to that thought; if that sentence is used literally and in that sense,
then, whatever the context, it expresses that thought. According to this
view, every thought is encoded by a sense of some sentence.
"On this view, it would be possible, at least in principle, to communicate thoughts linguistically without any appeal to inference or context (except, perhaps, for purposes of disambiguation)."
(D. Sperber and D. Wilson, Relevance: Communication and Cognition. Wiley, 1995)