Oooh, I realize, that 19th centure statement about this being 'necessary for the advancement of the human race' is just you trolling (or sarcasm?), and I fell for it. Doh!
Hell, we know what is edible and what is not because in the past few thousand years people accidentally killed themselves by eating crap.
To me that sounds a very Augustinian view, in which we can never claim to be innocent of anything, because our life is shaped by past sins which we inherit. Personally, I reject that completely; we should acknowledge that actions by others in the past shape the present, but not feel ashamed of them.
I guess I'm deeply bothered by proud statements of accomplishment that ignore profound and costly inheritance. PETA would never acknowledge that "cruelty-free" owes a debt to what they would term "cruelty". It's that lack of acknowledgement that bothers me.
The smallpox vaccine was famously tested on a child. He was given the vaccine and then injected with smallpox. All based on a crazy theory. And the smallpox vaccine saved millions because of that test.
There are many similar examples from the early days of medicine. People just tested things when they needed to. The first anesthesia had only been tested on a dog, once, before being taken to the operating table.
Now hundreds of people die every year because we can't test things quickly enough. Human testing is expensive, there are a ton of conditions that make it impossible in many cases, there aren't enough subjects, we can't release drugs if there is even the tiniest doubt they might not be safe or effective, etc.
Many lives could be saved if we applied a little utilitarianism. But instead we only selectively apply the argument where it's convenient. The greater good argument is fine as long as it's just hundreds of chimps and dogs being tortured for basically no gain. But don't risk a single child if it could save millions! Or even a consenting adult in many cases.
As for human trials, situation gets complicated because incentives. I'm all for consenting adults being given experimental drugs, but there are so many avenues for abuse (and people are so good at using them) that I'm not surprised it's heavily restricted or banned altogether. Because today's consenting adult will be tomorrow's prisoner forced to do it, next month's poor schmuck tricked into it by marketing, and next year's every one of us.