Well, a few things. First, don't presume either way until you have evidence. It seems that if you were following this guideline, you would not simply state,

Well, a few things. First, don't presume either way until you have evidence. It seems that if you were following this guideline, you would not simply state, As such, performing experiments on a dog to gain more knowledge is moral. Moreover, I am not sure how you are construing my claim as being positive. You said X is moral, and I said that such a statement depends on a source of knowledge that X is not immoral (that i.e., X is moral, your statement). There is no assertion I am making in there, except by implication, I am saying that facts about morality are like other facts, and need to exist and be demonstrable. You should be able to show them in some fashion. When you say dog experimentation is moral, you need to show the source of your facts. Again I guess I have to rely on your claim to know what and why morality is, because you don't want to explain that. Moreover, given that you seem to have some familiarity with philosophy, I don't understand why you would make such a comment about whether or not one ought to presume this or that without discussing the precautionary principle, which applies directly to the question at hand. The logic of the principle would seem to pose a direct challenge to your idea that one ought not presume either way. I'm sure you've read some books or some arguments which you are relying on here, but I can't take your claim that human morality is X, and that Y is moral, on face value. And I cannot think of anything you could possibly be relying on as your hidden source for these statements which is not also dependent on a set of assumptions.