to have no hesitation in stating, or dealing with, something, however unpleasant or awkward it is
Always used in the negative, this phrase dates back to the 16th century, originally as to make no bones at or in. It also occurred without a complement, as in its first recorded use, in The first tome or volume of the Paraphrase of Erasmus vpon the Newe Testamente (1548), by the English schoolmaster and playwright Nicholas Udall (1504-56); God has asked Abraham to sacrifice his son, Isaac:
He [= Abraham] made no manner bones ne stickyng *, but wente in hande to offer vp his onely sonne Isaac in sacrifyce.
(* The word manner (comparative of many) means more numerous, and stickyng (= sticking) means hesitation, scruple, delay.)
The modern form of the phrase is first recorded in The theatre of Gods judgements wherein is represented the admirable justice of God against all notorious sinners (1597), by the English clergyman and theologian Thomas Beard (died 1632); the chapter titled Of Incestuous persons contains this sentence:
Divers of the Roman Emperours were so villanous and wretched, as to make no bones of this sin with their owne sisters, as Caligula, Antonius, and Commodus.
It is generally said that to make no bones about something has its origin in an earlier phrase, to find no bones in something, meaning to find no obstacles or difficulties in something. This earlier phrase is first recorded in a letter that Friar Brackley wrote to John Paston in 1459 about a legal dispute:
Mayster R. Popy, a cunnyng and a crafty man, […] vndirtoke it, &c., and fond that tyme no bonys in the matere.
(Master R. Popy, a cunning and a crafty man, […] undertook it and, that time, found no bones in the matter.)
According to a popular theory, to find no bones in something originally referred to finding unwelcome bones in food, especially in soup. But this theory rests on a single reference, a passage from The Tunnying of Elynour Rummyng (circa 1516), by the English poet John Skelton (circa 1460-1529). This poem is about Elinour Rumming, an alewife who brews “noppy ale” (i.e. heady, strong ale), and the mixed company who throng to drink it; in the passage in question, a drunken woman called Ales (= Alice) has just fallen asleep in the alehouse:
Elynour toke her vp,
And blessed her wyth a cup
Of newe ale in cornes;
Ales founde therin no thornes,
But supped it vp at ones,
She founde therin no bones.
Eleanor took her up,
And blessed her with a cup
Of new ale in corns;
Alice found therein no thorns,
But drank it up at once,
She found therein no bones.
This passage does not necessarily have any connection with the phrase to find no bones in something. Or, if it has, it may well be wordplay, since the phrase is attested more than fifty years earlier. Additionally, no allusion to bones in food can be found, either in the above-mentioned 1459 text or in any of the 16th-century references.
More importantly, it is difficult to account for the shift from finding bones to making them. The phrases to find no bones and to make no bones are not necessarily related and a clue as to the origin of the latter might be provided by the following proverbs using the word bone:
Tonge breketh bone.
(The tongue breaks the bones, i.e. speech causes strife.)
Men sein that the harde bon,
Althogh himselven have non,
A tunge brekth it al to pieces.
(It is said that, although itself has none, a tongue breaks the hard bone to pieces.)
Faire speche makeþ many a good frend & holdeþ hol many a bon.
(Fair speech makes many a good friend and holds whole many a bone, i.e. prevents strife.)
Fayre wordes brake neuer bone.
(Fair words never break bones.)
This idea of the tongue, the words, capable of breaking bones might (at least better than unwelcome bones in soup) explain the origin and meaning of to make no bones about something.