The neutron does not know what mass it needs to have.
Protons have a stable mass of 1.67 times 10 to the minus 24th grams.
If the mass of the neutron were 2% greater than this, neutrons would quickly collapse
and atoms would become unstable.
In such a state of affairs, no element essential for life could exist, and the only element
in the universe would be hydrogen.
On the other hand, were the mass of the neutron to be slightly less, then in that case protons
would have an unstable structure.
That would mean the mass of the protons would be greater than the mass of the neutrons inside
the nucleus, and the protons would degenerate and turn into neutrons.
Physicists say that if the neutron mass were just two parts in a thousand smaller than what
it is, it would be impossible for atoms to possess the structure they have.
In short, there would be no such thing as life.
Current questions now arising in cosmology, elementary particle physics, and microbiology
have an obvious metaphysical or religious content.
The existence of the universe requires me to conclude that God exists.