Could animals talk?

[The Saucepan Man]

Originally Posted by Tuor of Gondolin

There is also a line of argument that sentient animals were actually maia, for example, the great eagles, and the giant mirkwood spiders offspring of Ongoliant.

Would that include the ravens of Erebor and the thrush that spoke to Bard? Or the fox that witnesses the Hobbits travelling through the Shire?

I'm not a fan of this theory or the theories that have the talking animals as merely repeating learned patterns or the products of Hobbitish whimsy, as they all rather detract from the charm of the Hobbit and the early chapters of LotR, which suggest to me that all of these creatures (including the eagles and the spiders) are just what they appear to be - sentient (non-Maiar) animals.

Whoever said that such things could not exist in Middle-earth anyway?