J. R. R. Tolkien, the accomplished translator of works such as The Red Book of Westmarch, pointed out later in his life that the Red Book's record is inevitably partial. If there were any good orcs, he writes, they would doubtlessly have been exterminated by the evil tribal governments to which our records clearly testify. We can even see hints of such exterminatory policies when Mr. Sam Gamgee records Shagrat and Gorbag wishing they could strike out on their own, but lamenting how the Mordorian government would crack down on any such plans.

Contemporary philosophers hinted that good orcs were possible. Finrod Felegund, in his monumental Athrabeth, argued that not even all the power of Morgoth could annihilate the good from the soul of a Speaking Person. While others such as Pengolodh (author of the well-known Quenta Silmarillia) did reject Finrod's philosophy, the universally-agreed Elven Laws of War decreed that mercy be given to any orc who asked for it. Sadly, we don't know what motivated this offer: was it merely Finrod's philosophy? Or had elves met an actually good orc? The surviving records don't say.

So, in short, while we don't have clear evidence, there are hints - including some contemporary - that not all orcs were evil.