Anslem's argument is sound.

[henryp]

If you don't value actual life, what do you value?

So this is where it gets tricky, because I'm going to say value to mean one thing, and you think of it as another.

I value donuts.  They are delicious.  I do not value brussel sprouts.  They are gross.  

I don't believe my valuing donuts but not brussel sprouts says anything about donuts or brussel sprouts having any intrinsic value. 

I do value my life.  But in the same way I value donuts.  It's something I like.  That most of us like being alive does not make life inherently valuable.  It's just a common opinion.  Just like most people liking donuts doesn't make them more valuable than brussel sprouts, which are generally despised.  

What I think you need for your argument is a way to show human life is valuable that isn't based on an opinion, as you can see with many examples that opinion of value and intrinsic value (such as with donuts) are not connected.