Recently, my phone gave me some trouble and I sent a text to my wife and kids to tell them that I might be uncontactable. As I was texting to them, I decided to type 'incontactable' instead just to see their reaction. One of my kids immediately replied, 'You mean "uncontactable"?' That gave me the opportunity to launch into a full explanation which, because of its length, I did by email. You see, quite apart from the peculiarities of the 'in-' and 'un-' prefixes, the word 'uncontactable' itself is rich with interesting little nuggets of history.
But before you stop reading this post, I should make it clear that I am not repeating what I wrote in that email. As I have promised some of my friends who find my posts tediously boring, I will keep every blog post of mine short. I will just talk about the 'in-' and 'un-' prefixes with respect to one word - 'comparable'. I will not stray beyond this, not even to explain why we say 'unable' but 'inability' as the title of this post clearly demonstrates.
Today, most people will say 'incomparable' rather than 'uncomparable'. My computer automatically underlines 'uncomparable' in red to indicate that it's misspelt. But both words have been around since Chaucer's time and they both carried only one meaning: 'beyond comparison'. In the early 17th century, 'incomparable' acquired a secondary meaning: 'that cannot be compared'. Two centuries later, around the time when Jane Austen wrote her novels, this same secondary meaning became attached to 'uncomparable' and over time, the first meaning of 'uncomparable' went into disuse and finally passed into obsolescence, leaving it with only the secondary meaning it acquired in the early 19th century.
In the first half of the 20th century, a renowned grammarian suggested quite wisely that 'incomparable' should be used only for the first meaning and 'uncomparable' the second meaning. That would make the language a lot more precise. Henry Fowler who was very quick to make his own recommendations on such matters pertaining to the language, was strangely silent on this.
But as Samuel Johnson observed as long ago as the 18th century, language is 'too volatile and subtile for legal restraints; to enchain syllables, and to lash the wind, are equally the undertakings of pride, unwilling to measure its desires by its strength'.
Usage, the indomitable wind of change, refused to obey the ruling of that grammarian and today, 'incomparable' carries both meanings and 'uncomparable' is as good as moribund.
Years from now, if I text my kids the word 'uncomparable', they'll probably reply, 'You mean "incomparable"?'