words like ‘sex’ and ‘rape’ that are used to describe things have meaning by virtue of a degree of convention… are you hoping to abandon all reliance on convention?
Yes, but I should point out that there is a further difference - that even when these are used to describe qualitative differences - such as reasonably demonstrated consent - this in itself has no normative content. We talk about this as being important because it is important to most of us - and because the things involved are important to us. So it would make sense that arbitration would involve ideas of common interest and understanding. What is not rational is to take this as a demonstration or instantiation of a ‘moral necessity’, a ‘categorical imperative’ etc. - these are simply elements of human behaviour. To argue consequentially is one thing, to argue about ‘good’ and ‘evil’ is to reduce the argument to a discussion about feelings.