Magic.
It was something that—by definition—a supernatural phenomenon that defies all scientific law. Samuel doesn't believe in anything that cannot be explained by scientific laws or theories. Anything derived from a supreme being makes him lose interest. Perhaps it was rooted in the people around him.
When his parents died, they told Samuel he should cheer up.
'Your parents died for a reason…'
'There must be a plan ahead for you.'
He was catholic, and so he was surrounded by relatives who are avid worshippers, along with churchmates of his parents. They all comforted the child Samuel, and he knew by that time that they meant well. He knew that himself.
But something was unsettling about it—about that certain phrase.
'For a reason.'