I'm looking for information about a theory that I can't remember the
name of. It basically says that God must exist because how else can we
explain the beginning of the universe. I think its called theory of
first instance or something similar... it might also be known by a
Latin name as well (something similar to prima noce - although I think
that's from 'Braveheart'!)

Prima noce is first night. You are probably thinking of primum mobile
- the first mover. According to this argument God is the prime cause
or first mover in the universe. All other causes can be traced back to
God who is the first cause of the series and the ultimate cause of
everything. A varian argument is that all things which move have
motion transmitted to them. This too can be traced back to God as the
unmoved first mover of everything.
This kind of argument for the existence of God is called the Causal
argument or the Cosmological argument. St Thomas Aquinas used this
sort of argument in several of his Five Ways of proving the existence
of God.
Incidentally, there are a lot of philosophical flaws in the arguments,
which I could mention if you're interested.
Amber

Amber, I would be very interested in the flaws in the arguments, if
you can post them... thank you.

rai...

Another useful term to use in searches on this would be
"first cause, uncaused".

There are several problems, including:
1. How do we know that there is a starting point? Maybe the series of
causes goes back to infinity.
2. Even if it's true that every single thing has a cause, it doesn't
follow that there is one cause (God) for everything. A parallel is
that every single human being has a mother but it doesn't follow that
there is one person who is the mother of us all. This faulty move in
logic is called a quantifier shift fallacy.
Best wishes,
Amber

Thanks Amber... its good to have a counter-argument...