Writer's choice

links for st thomas

http://www.newadvent.org/summa/1002.htm

This link brings you to an excerpt from a mature work of Aquinas', his grand synthesis of knowledge call the "Summa Theologica" (a "summary" of the study of God). In it, you will find the famous "five ways" Aquinas offered for the proof that God exists.

We are offered:

(1) an argument "from motion" (if some things are in motion, then the motion must have been actualized by something other than itself, which is itself in motion; but this cannot continue infinitely, thus there must be a first mover which imparts motion to everything with motion, but which is itself pure, fully actualized motion).

(2) an argument "from the efficient cause" (everything has some cause which is responsible for its having come into existence; but if this cannot continue on infinitely, since this would be the same as saying that there is no first cause and lead to the absurd conclusion that nothing could be brought into being, there must then be some single cause that is first responsible for the existence of everything)

(3) an argument "from possibility and necessity" (if there are only beings that exist contingently, such that it's possible for them not to be, then, at some point, there may be nothing at all, which is absurd: how can something come from nothing? Thus, there must be one being which is necessary -- that cannot fail to exist).

(4) an argument "from gradation" (from the idea that there is a hierarchy of perfections, that some things are more perfect than others, some less, and so on, ... which suggests that there must be something which has fully manifested all perfections).

(5) an argument "from the governance of the world" (the idea that all things tend towards some ultimate end, and that only an intelligence can be the true motive force behind such activities).

William leibniz

http://plato.stanford.edu/entries/leibniz/#OveLei