Allow me elaborate further:
All other things being equal: an act is unethical. (U)
An act which, all other things being equal, is unethical, is necessary in a certain context in order for the subject to act in accordance with his hierarchy of values; and is therefore -- ethical. (E)
So it is a contradiction to say (E) entails (E & U); because for (E) to entail (U) would mean (U & ~U); but (U) is not (U) in such a case, because -- not all other things are equal. Theoretically (although there are, perhaps, some acts I would be willing to make exception for), only time you can say (U) is not subject to context is if you accept some categorical imperative. And if (E) entails (U), then (U) is (~U).
-- Updated April 3rd, 2012, 4:42 pm to add the following --
Jposamen wrote:Some "acts" are unethical, right? Some are ethical right?
There are acts that you can describe as ethical/unethical -- all other things being equal. But "ethicalness" is always subject to context; unless you accept a set of moral imperatives, which I do not.
Now, there are acts for which I cannot conceive of a context in which it would be ethical to perpetrate them; e.g., molesting a child, or committing genocide, but almost all other actions can be construed as ethical in some context.
E.g., it is not unethical to kill someone in self-defense.