That is a fair question and within the 'safety' of this forum I would suggest every individual has his own moral compass - for example...
I used to absolutely love organised hare coursing with both the Greyhound clubs and the Whippet club. The rules were totally in favour of the hare and I doubt if more that 7 or 8% were caught. In the case of the Greyhounds, if they killed at all it would be within seconds. I remember watching a dog called Peasedown Erin and he often pulled down within 20 seconds.
However, on some of the days out with the lurcher clubs, I didn't enjoy prolonged courses made by the Saluki bred dogs. These dogs had phenomenal stamina - seeing was believing. I found no enjoyment in watching a poor hare, that had used every trick in the book and was proven to have amazing agility, speed and stamina, be worn down in courses lasting many minutes. Watching a hare, pushed into the centre of a huge field be worn down to a trot, until it emits a pitiful cry - is not good sport in my book.
Yes - both could be classed as 'hare coursing' but, personally, for me, the two examples are as different as chalk and cheese.
Likewise, anyone with any experience at all could quickly explain the difference between ratting with terriers and Stag hunting. We all have to make our own minds up what is acceptable to us.