Meanings of keenly intelligent in English

As he approached the village, his glances became more and more keenly intelligent.

He is too keenly intelligent, too sharply sensitive, successfully to endure.

But he was also keenly intelligent.

Although his grace of address was involuntary, like any keenly intelligent and retrospective man, he could not avoid being aware of it.

The impassibility of that fine head, the fixity of that glance, cover irresolution and weakness, which the keenly intelligent and sarcastic smile belies.

'Nothing,' I say, under this keenly intelligent gaze of hers, that still doesn't quite know who I am.