The Design Argument looks at odd features of our world, like how orderly it is, how complex it is or how suitable it is for human life. The Cosmological Argument takes a step further back and asks where the whole world comes from in the first place.
The Greek word for “world” is kosmos, meaning everything that exists and not just our planet. Scientists also investigate where the world has come from, but a lot of religious believers find scientific explanations unsatisfactory. Ultimately, scientific explanations currently go back to the Big Bang 14 billion years ago and they conclude that everything comes from that. Many religious believers want to ask a more important question: Why did the Big Bang happen? What caused that?
In the words of Gottfried Leibniz:
Why is there something rather than nothing? - Gottfried Liebnitz
But this is not a question science can answer…
To religious believers, God seems a simple, obvious answer to the question of why the universe is here, of where it all comes from.
In the beginning God created the heaven and the earth - Genesis 1: 1
The various different cosmological arguments (the name was given to them by Immanuel Kant in 1781 but they’ve been around much longer) all try to show that "God" is the best answer to this question. However, atheists deny that God is the best answer. To them, there’s no need to bring God into it. Some of them argue that the universe has always been here in some form or other; others argue that the universe needs to be accepted as an inexplicable mystery - a "brute fact".
I should say that the universe is just there, and that's alL - Bertrand Russell
In fact, there are several cosmological arguments with different emphases In these arguments, we look at the world around us, look at creation and how things function within that world, and then conclude from this that there must be something which brought this world about.
The key feature of the world is CONTINGENCY; that is to say, that everything relies on something else for either its movement or its own existence. The arguments move from contingency to the existence of a non-contingent God.
Earlier versions of this argument focus on broad examples of contingency, such as the fact that everything is in motion, or has energy, or has a cause or a beginning. Later, more sophisticated versions of the argument focus on contingency itself: everything seems to be dependent on something else and nothing exists "on its own" or "in its own right".
Don't be one of those people who think the "Big Bang Theory" disproves God. In fact, the BBT supports the Cosmological Argument because it shows the universe had a definite beginning. Some scientists question the BBT and, if it were disproved in favour of a theory that the universe has always existed, that would weaken the Cosmological Argument.
Faced with contingency, philosophers have proposed variations on this argument:
P1 (premise 1) Everything depends on something else that came before it P2 (premise 2) This chain of events or explanations cannot go back infinitely (infinite regress) C (conclusion) There must be something that exists necessarily, upon which everything else depends
This NECESSARY entity doesn't need a cause or a beginning; it doesn't depend on anything or come from anywhere. It exists "for itself" and "in its own right". It is the explanation that explains everything else, the thing that "sets the ball rolling".
Mr McMillan offers excellent videos on his Religious Studies site
Remember, the Cosmological Argument looks at the ORIGIN of the world and proposes that there must be an EXPLANATION for its existence.
It's not asking about the STRUCTURE of the world - that's the Design Argument.
Make sure you focus on BEGINNINGS, ORIGINS, CAUSES and CREATION... not design, order or purpose
This is an easy confusion to fall into since religions like Christianity, Judaism and Islam believe in a God who is both a Designer AND a Creator. Not all religions merge these two roles. Aristotle and Plato believed in a God who was responsible (almost accidentally) for the creation of the universe, but another, different God (called "the Demiurge") who was responsible for designing it.
If you want to criticise a philosophical argument, you can question whether it is SOUND or whether it is VALID.
A sound argument has premises which are true.
Is it true that everything has a beginning, cause or explanation or could things go back infinitely?
Is it true that the universe must have an explanation?
Is it true that only the God of the Bible can be that explanation?
A valid argument has conclusions which proceed logically from the premises.
If everything must come from somewhere, does that apply to God too?
If not, could the universe also be something that doesn't have to come from something else?
Thomas Aquinasfamously concluded the Cosmological Argument with the phrase "et hoc dicemus deum" - "and we call this thing God". Some people think Aquinas is making a big leap here. Does it automatically follow that the creator of the universe is the God of the Bible?
Crash Course Philosophy sum up the Cosmological Argument - with a focus on 4 of Aquinas' "Five Ways"