Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Post History

22%
+0 −5
Q&A How did 'to wit' shift (from "to know") 🡺 to mean 'that is to say'?

Unquestionably, "wit" or "knowing" are concepts distinguishable from "saying". Thus how did 'that is to wit' shift 🢂 to denote 'that is to say; namely'? wit Both the noun wit [OE] and the verb...

1 answer  ·  posted 3y ago by PSTH‭  ·  last activity 2y ago by gmcgath‭

Question etymology
#7: Post edited by user avatar PSTH‭ · 2022-06-20T14:13:10Z (almost 2 years ago)
  • How did 'to wit' shift to denote 'that is to say'?
  • How did 'to wit' shift (from "to know") 🡺 to mean 'that is to say'?
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit_ (mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "wit" or "knowing" are concepts distinguishable from "saying". Thus how did 'that is to wit' shift 🢂 to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit_ (mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#6: Post edited by user avatar PSTH‭ · 2021-11-13T07:01:57Z (over 2 years ago)
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit_ (mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit_ (mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#5: Post edited by user avatar PSTH‭ · 2021-06-16T06:55:06Z (almost 3 years ago)
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit_ (mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#4: Post edited by user avatar PSTH‭ · 2021-05-27T07:02:54Z (almost 3 years ago)
  • How did '[that is] to wit' shift to denote 'that is to say'?
  • How did 'to wit' shift to denote 'that is to say'?
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'that is to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#3: Post edited by user avatar PSTH‭ · 2021-05-27T07:01:48Z (almost 3 years ago)
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote ['that is to say; namely'](https://en.wiktionary.org/wiki/to_wit#Etymology)?
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#2: Post edited by user avatar PSTH‭ · 2021-05-27T07:00:46Z (almost 3 years ago)
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote
  • >###wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column.
  • I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
  • Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote
  • >### wit
  • >Both the noun _wit_ [OE] and the verb [OE] go
  • back ultimately to the Indo-European base
  • _*woid-, *weid-, *wid-_. This originally meant
  • ‘see’, in which sense it has given English _visible_,
  • _vision_, etc, but it developed metaphorically to
  • ‘know’, and it is this sense that lies behind
  • English _wit_. The noun to begin with denoted
  • ‘mind, understanding, judgement, sense’ (a
  • meaning preserved in expressions such as ‘keep
  • one’s wits about one’ and ‘slow-witted’), and the
  • modern sense ‘clever humorousness’ did not
  • begin to emerge until the 16th century. The verb
  • has now virtually died out, except in the
  • expression _to wit_. _Witness_ is etymologically the
  • state of ‘knowing’. Other English words that
  • come from the same Indo-European base or its
  • Germanic descendant include _guide, history,
  • idea, story_, and _twit_.
  • John Ayto, *Word Origins* (2005 2e), p 549 Left column. Below I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):
  • > "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"
  • from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see."
  • >The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).
#1: Initial revision by user avatar PSTH‭ · 2021-05-27T06:58:58Z (almost 3 years ago)
How did '[that is] to wit' shift to denote 'that is to say'? 
Unquestionably, "knowing" isn't the same concept as "saying". Thus how did 'to wit' shift to denote 

>###wit 

>Both the noun _wit_ [OE] and the verb [OE] go
back ultimately to the Indo-European base
_*woid-, *weid-, *wid-_. This originally meant
‘see’, in which sense it has given English _visible_,
_vision_, etc, but it developed metaphorically to
‘know’, and it is this sense that lies behind
English _wit_. The noun to begin with denoted
‘mind, understanding, judgement, sense’ (a
meaning preserved in expressions such as ‘keep
one’s wits about one’ and ‘slow-witted’), and the
modern sense ‘clever humorousness’ did not
begin to emerge until the 16th century. The verb
has now virtually died out, except in the
expression _to wit_. _Witness_ is etymologically the
state of ‘knowing’. Other English words that
come from the same Indo-European base or its
Germanic descendant include _guide, history,
idea, story_, and _twit_.

John Ayto, *Word Origins* (2005 2e), p 549 Left column.


I quote Etymonline on the verb ["wit"](https://www.etymonline.com/search?q=wit):

> "to know" (archaic), Old English _witan_ (past tense wast, past participle witen) "to know, beware of or conscious of, understand, observe, ascertain, learn,"       
from Proto-Germanic _\*witanan_ "to have seen," hence "to know" (source also of Old Saxon _witan_, Old Norse _vita_, Old Frisian _wita_, Middle Dutch, Dutch _weten_, Old High German _wizzan_, German _wissen_, Gothic _witan_ "to know"), from PIE root [\*weid-](https://www.etymonline.com/word/*weid-) "to see." 

>The phrase _to wit_, almost the only surviving use of the verb, is first recorded 1570s, from earlier _that is to wit _(mid-14c.), probably a loan-translation of Anglo-French _cestasavoir_, used to render Latin _videlicet_ (see [viz.](https://www.etymonline.com/word/wit)).