Aquinas attempts to argue for the existence of God. His logical argument states natural things appear to be directed towards a certain goal and so this must explain a higher power as director. 

He said "hence it is plain that natural bodies achieve their end, not fortuitously, but designedly. Now whatever lacks knowledge and intelligence; as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God"

THE ARCHER ANALOGY 

Aquinas used the analogy of an archer (in this case, God) directing the arrow(all natural bodies) he shoots towards a certain target (goal in life).                         

                                                        >>--------->          

We naturally infer from this that the arrow needs to be shot by an intelligent, higher power otherwise it has no purpose. 

However, does this 'prove' the existence of God?