A) The cosmological argument is to prove the existence of God. In this type of argument we are looking at cause and not design. This type of argument is an aposteriori argument because it is based upon experience. Thomas Aquinas puts the key ideas into 3 ways. First way is, motion/change. Nothing can move by itself or change itself. The first thing to have moved must have been moved by something else and that thing therefore must be God.
" It is certain and evident to our senses, that in the world some things are in motion. Now whatever moves is moved by another. It is therefore impossible that, a thing should be both mover and moved. If that by which it is moved be itself moved, then this also must needs be moved by another. But his cannot go on to infinity, because then there would be no first mover and subsequently no other mover.
Therefore it is necessary to arrive at a first mover, moved by no other, and this everyone understands to be god"
He calls God the unmoved mover because God did not have to be caused.
The second way in which he argues for the existence of God is by saying that everything that exists has a cause. Nothing can come to existence without being caused. Everything that exists depends on something causing it; he concludes he's argument by saying that God is the first cause. He did not have to be caused as he was always there.
"The second way is from the nature of efficient cause. In the world. We find there is an order of efficient causes. There is no case know (neither is it indeed possible) I which a thing is found to be the efficient cause of itself, for so...