Consider the similar task of counting humans. The American constitution originally considered Native Americans as equivalent to 3/5 of a person. We now count them as a full person. What changed other than perspective/brain state?
Even with sheep, consider the possibility that out of say 10 of the sheep you counted, one or all of those sheep are pregnant. Not only that, but you don't know which are or may be pregnant, or how many sheep they may be pregnant with. Does an unborn sheep even count as a full sheep? And yet you counted 10 sheep, and if counting sheep works without changing perspective, then there are 10 sheep regardless. I'm not sure I would agree with that.
If you change your definitions you will very likely end up with different results.
I, as someone who hates arguing about definitions, will be the first to agree with you that there exists no “true” definition of sheep or, for that matter, humans. Definitions are just lists of properties and conditional statements to which we assign certain words. There is nothing true and nothing magic about them. They help us communicating and that’s that.
My statement about sheep is useful (true?) only if all the concepts I use in my statement are properly defined. I can’t just start to count pregnant sheep differently because then my statement isn’t useful (true?) anymore. Counting pregnant sheep differently wouldn’t help me tell whether or not all sheep are back in the pen at the end of the day and that’s the whole point of the statement. I’m not making a moral statement about whether or not unborn sheep count. That has got nothing to do with my statement and is very much beside the point.
It’s not that surprising, actually. If you change a statement which has proven to make good predictions by redefining one of its concepts, you will likely break the statement. It won’t make good predictions any more.
Counting pregnant sheep differently wouldn’t help me tell whether or not all sheep are back in the pen at the end of the day and that’s the whole point of the statement. I’m not making a moral statement about whether or not unborn sheep count. That has got nothing to do with my statement and is very much beside the point.
Whether it's beside the point depends on your perspective :). I spent a few days working on an actual sheep farm in New Zealand, and whether or not your sheep are pregnant is actually a highly relevant fact. Whether or not a sheep that starts out pregnant is still pregnant at the end of the day is also highly relevant. I wasn't trying to say that unborn sheep have anything to do with 'morality', but they are very much not beside the point.
It’s not that surprising, actually. If you change a statement which has proven to make good predictions by redefining one of its concepts, you will likely break the statement. It won’t make good predictions any more.
This is actually one of the salient points of post-modernist thought, with the caveat that post-modernism argues that all statements are always changing, 'definitions' of concepts are always changing. Take our sheep debate for example -- you make statements that are useful to you, and then I respond by interpreting the statements so that they are useful to me, and vice versa.
Even with sheep, consider the possibility that out of say 10 of the sheep you counted, one or all of those sheep are pregnant. Not only that, but you don't know which are or may be pregnant, or how many sheep they may be pregnant with. Does an unborn sheep even count as a full sheep? And yet you counted 10 sheep, and if counting sheep works without changing perspective, then there are 10 sheep regardless. I'm not sure I would agree with that.