a decision being made purely based on the philosophical concept of intelligent life being valuable
I guess therefore that the premise of your question is an implied syllogism, i.e.:
- Intelligent life is valuable.
- Human life is intelligent.
- Therefore Human life is valuable.
If so, that seems to me to contradict the following subsequent statement in the argument:
science tell us "A human fetus is both alive and human"
Perhaps a human fetus isn't "intelligent life" (at least not until later in life – for example in early life I think that the brain exists but hasn't been hooked up yet, and therefore it must fail most definitions of "intelligent" I could think of).
I say "contradict" because, if you're saying that "a human being is valuable because it's intelligent", then given that a (sufficiently young) fetus is not "intelligent", you might then have to grant that a fetus is not human (if being "intelligent" is a necessary attribute of being human).
Or, if you kept the "a fetus is a human" definition, then the argument might break at this statement:
one human life is not more valuable than another
If one human is intelligent (because it's a living adult) and another is not (because it's a young fetus which hasn't yet developed a nervous system), and if human life is valuable because it's intelligent, therefore one would be more valuable than another.
I suspect that there's a problem caused by using an adjective as a noun. The word "human" can be used as an adjective or a noun. It can be used as an adjective, e.g.:
- Human being
- Human fetus
- Human fingernail
- Human gamete
These take the same adjective but are not the same "things". Your adding the noun "life" in your statements lets you say, "A and B are both human life, C and D are not human life", which lets you equate A and B. But notwithstanding your equation they're still not the same thing.
I suspect that "a fetus is a human being" implies some type of reification.
Statements like "all human lives are equal valuable and equally protected" is only more-or-less true, and in limited/specific circumstances. For example people are naturally inclined to protect their family and friends more than they protect strangers and enemies. And for example the national law (in many though not all countries) is more inclined to protect post-birth independent human life more than pre-birth non-independent human life.