Wait. Is being sentient equal to having your own consciousness? I suppose so; how can you be aware of the things around you if you aren't conscious?
Are computers sentient? Or a thermometer at least. What I thought of the Ring before was like a thermometer--the mercury rises as a result of thermodynamic expansion. The Ring "awakened" when it "detected" Sauron stirring, and it responded to the Nazgul because that is its property, it could not do otherwise much in the same way Vitamin C is an acid forever and ever. The Ring "spoke" I think, because it was so very near its Master that Sauron could manipulate it. I don't think the Ring was separate from Sauron--he poured too much of his soul in that
thing he made that once it is broken, he shall be broken too.
Orcs I think are a different matter. It's like brainwashing a people--you do get to control their ideologies and stuff, but they're still alive, and there can always be some very small hope of "redeeming" them. Morgoth created the first Orcs out of the Avari, right? Somewhere in the Sil it says something like he cannot make live things, he can only mar. Think of dogs and other pets... you may train it to sit and eat and stuff, but you don't really control it, do you?
The Silmarils, I think I've said it in my post
here.
Nah I'm contradicting myself again.