[Nimajneb]

My point is simply that without proof and in light of the fact that Bonds was a great homerun hitter, we ought to let this pass.

Why? The only way to have acquired "proof" of the type you apparantly demand is if Bonds had walked up to you and said "here, will you take pictures while Greg here injects me in the back? Oh, and here's a sample of what he's using on me, we wouldn't want to be able to claim it was a flu shot later, ya'know."

You seem to be contradicting yourself.

Then you seem to be misunderstanding...

Let's assume that there is a substance that enhances performance and causes no health problems. Should athletes be prohibited from ingesting that substance?

If legal and equally available to all players, and allowable under the rules of the game, then no: it shouldn't be prohibited. If the legality is more of a technical oversight than genuine legitimacy (i.e. andro) then that's a dicier question.