Viviane,
I experimented with your statement that in science ( from Latin scientia, from scir e‘know’, hence denoting knowldge”) there is no difference between HOW and WHY.
When my daughter (9 year old) came from the school, I asked her:
“How did you go to the school?”
Mummy dropped me in the school as usual on her way to the Hospital (She runs a hospital, and also works there as MD)
“Why do you go to the school?”
You must be kidding, Dad.
“No, I am serious. I just want to know how answer to the question HOW and WHY? And I want to report to one of my friends. Tell me, WHY do you go to school?”
Because I want to build my character and equip myself for a successful career like my mom” (my wife spends bulk of her earnings on three orphanages run by Catholic nuns and is widely respected by the community). You know my school Principal described my mom as an angel in human form.
“You don’t want to become like me?”
Who will waste the best part of life in the sea (I was working in the Merchant Navy)?
Viviane, You see how people differentiate between HOW and WHY
Similarly, science may explain HOW life originated?
But it cannot answer WHY did it appear from non-life only to disappear after evolving into homo sapiens—a wonderful journey started from matter and returns to matter in the end—WHY?