We could formalise what you say you're after like so:
Like a few here, I did some law once - remember *mens rea* and *actus reas* (spelling?)? If rape is criminal (which it should only be if we think it is bad) then anyone inhabiting that society who forces sex on someone else is guilty of rape *if they knew that they were doing a bad thing while they were doing it*. We're talking 'good' and 'bad' - and in terms of a necessary and necessarily generalised/able, or whole-of-community, abstraction. The rapist might think it a good thing from his/her own point of view, *but is generally held consciously to know what is good for the goose is not good for the flock*. S/he's in the lifeworld (where it's bad) and, as such, accountable to the system (where it's criminal).
All of that - from conceptual abstractions, through lifeworld norms, to the institutions that constitute the system - require peculiarly human capacities. Not only is there no such thing as rape outside the human world, but it's absolutely conceivable (not to mention empirically demonstrable) that the notion of rape, what is and is not rape, the degree of badness of rape, and the criminality of rape are all up for grabs - varying across human communities as they do.
Ergo, animals can't rape - and in different times and places, eg. husbands could not be held to rape thier wives, masters their slaves, clients (anyone?) a prostitute, an 'adult' a 'child' and so on. *All based on shared 'negotiable' (worth the scare quotes, as many use this word even where the participants are not conscious that negotiation is in progress) meanings* - not available to the non-languaged - and all variable over human time and space for precisely that reason.
Which is an even longer way of saying what Daniel said so eloquently, but extends the dry tendrils of Habermas's abstractions ever further across the once colourful playground that was LBO-Talk.
Cheers, Rob.
>Daniel Davies wrote:
>
>> Errrr....I'm clearly missing something cos this seems quite
>> straightforward. Apes do groom and manatees do nurture, because these are
>> not acts which presuppose a set of human categories. Birds tweet, but
>> don't really sing; magpies take but don't really steal, because singing
>> and
>> stealing do presuppose these human categories. Male animals force females
>> to mate, but only humans rape.
>>
> True. But there is a tautology here, no? "Forced copulation in
>animals is not comparable to forced copulation in humans because one
>concerns humans and the other concerns animals." More is needed to give
>this argument force.
>
> Seth