One can do that metalingual job in various ways, but, as far as I can tell, one can’t avoid it.
“(I saw) a dog, specifically, a beagle,”
or if you’re willing to sound a little old fashioned and long-winded:
“(I saw) a dog, or, more specifically, a beagle, or yet more specifically, Fido.”
So the construction exits and isn’t quite as contrived as your version. But I agree, it doesn’t exactly roll off the tongue. And it only works as a noun clause, rather than an entire sentence.
And asserting that you saw something is different from asserting what something is. You can do the latter without ever having seen that something yourself, but you know about it because you read it in a book or someone told you about. So it’s not semantically equivalent. As you say, it works only as a clause, not as a free-standing sentence.
“(I saw) a dog, specifically, a beagle,”
or if you’re willing to sound a little old fashioned and long-winded:
“(I saw) a dog, or, more specifically, a beagle, or yet more specifically, Fido.”
So the construction exits and isn’t quite as contrived as your version. But I agree, it doesn’t exactly roll off the tongue. And it only works as a noun clause, rather than an entire sentence.
And asserting that you saw something is different from asserting what something is. You can do the latter without ever having seen that something yourself, but you know about it because you read it in a book or someone told you about. So it’s not semantically equivalent. As you say, it works only as a clause, not as a free-standing sentence.