[The Saucepan Man]

But I suppose this is what happens when you start out writing fairy tales & & end up writing high mythology. Faerie contains monsters, who are just 'monsters'. In Faerie Goblins, Trolls & Ogres simply exist, & have as much right to exist as Elves, Gnomes, & talking foxes! There's no 'moral' dimension as such.

Spot on, davem. That, I think, summarises the problem of the existence of Orcs (and also Trolls) in Middle-earth in a nutshell. As you say, in "Faerie", these creatures have a right to exist as much as any other. Evil is just another "way of life". A rather banal, but nevertheless illustrative, example from my own (alas now historical) experience is the concept of alignment in role-playing games such as Dungeons & Dragons. Every creature has its own alignment which is a combination of opposing concepts: Good v Evil, Lawful v Chaotic. Races are ascribed their own generic alignment. For example, Orcs are lawful Evil (living within an ordered but inherently evil society). No one alignment is, objectively, the "correct" way to behave.

In this kind of a world (similar to the world of "Faerie"?), evil is an end in itself. Evil creatures have their own Gods and pursue their own evil ends. Neither their Gods nor the Gods of the creatures of good alignment were responsible for the creation of the world, but are vying for control of it. In contrast, however, evil in Middle-earth is objectively "wrong", a corruption of the plan set in motion by the being responsible for the world's creation. But, if evil is objectively wrong, it seems inherently unfair that creatures such as Orcs have no choice but to be evil.

As you say, davem, I think that it is the tension inherent in combining the world of "Faerie" with a Christian world-view that give rise to the difficulties that we have with the moral status of Orcs. And it is this, I think, that led to Tolkien revisiting his ideas on the origins of Orcs in his later years. Portraying them as simple "beasts" or automatons resolves these problems, but does not sit well with the characterisation of the likes of Shagrat and Gorbag in LotR (nor, indeed the quasi-independent Goblins of The Hobbit).