Let me start this discussion with a conversation that I’ve had with a large handful of atheists. It goes a little like this:
Me: “God exists”
Atheist: “I want evidence”
Me: “Define ‘evidence’ for me”
Atheist: “Facts or information indicating whether or not a belief is true”
Me: “I agree with that definition of evidence. Do you analyze arguments?”
Atheist: “An argument is not evidence”
So, the burning question here is:
What exactly is the relationship between evidence and arguments? ***
First, lets start with definitions.
What is evidence?
What is an argument?
Atheists always say they want evidence for God’s existence, and rightfully so. But what is evidence? There are a lot of really interesting articles on the nature of evidence, but lets just look at 3 sources.
- The Internet Encyclopedia of Philosophy has a really interesting article, check it out. In an epistemological sense, evidence is considered to play a role in justification for a particular belief.
- Dictionary.reference.com defines evidence as “that which tends to prove or disprove something; ground for belief; proof.”
- Oxforddictionaries.com defines evidence as “the available body of facts or information indicating whether a belief or proposition is true or valid”
All of this together should give us a usable, uncontroversial definition of the word evidence. Evidence can be defined as the available body of facts or information which tends to prove or disprove something, usually associated with the justification for beliefs.
That definition of evidence seems to fit well with the three references used above, as well as our everyday understanding of evidence. We could get a lot deeper into this discussion (obviously), but it is not necessary for the goal of this post.
Now that we know what evidence is, what is an argument? The discussion on the nature of arguments is equally (or possible more) complex than the discussion of evidence, but we’re not going to go deeper than we have to. And, for the sake of consistency, I’ll use the same 3 sources.
And as a point of note, I am using the term argument in it’s technical sense; not synonymous with bickering or quarrelling.
- The Internet Encyclopedia of Philosophy has, again, a very interesting article on arguments. I’d encourage you to read it. Put very briefly, an argument is “a collection of truth-bearers … some of which are offered as reasons for one of them, the conclusion” and “a typical use of an argument is to rationally persuade its audience of the truth of the conclusion.”
- Dictionary.reference.com defines an argument as “a statement, reason, or fact for or against a point.”
- OxfordDictionaries.com defines an argument as “a reason or set of reasons given in support of an idea, action or theory”
All of this together should give us a usable, uncontroversial definition of the word “argument”. An argument can be defined as a collection of truth-bearing statements, reasons or facts used in support of an idea, theory or belief. Arguments are used to rationally persuade its audience of a particular conclusion.
Just like my definition of evidence, the discussion of arguments can go much, much deeper than this. But for the goal of this post, this definition works well.
Given the two definitions above, both arguments and evidence deal with coming to conclusions (either affirming or denying something). They both also deal with supporting beliefs, and they both deal with reasons and facts.
So what is the difference?
It looks like the definitions of evidence and arguments overlap in all the important categories, except one. Arguments deal with “truth-bearers” (a term used by the IEP), which are statements, beliefs, or propositions that can either be true or false.
For example, if I say, “All men are mortal”… that statement is either true or false. The same goes with the statement “Elijah is a man”.
So an argument is a series of truth-bearers that lead to a conclusion. Take the two examples I used above. From those two statements, what conclusion can be reached?
- All men are mortal.
- Elijah is a man.
- Therefore – Elijah is mortal.
We have good evidence to believe the 1st statement.
And, considering I am the Elijah spoken of in the 2nd premise, we have good evidence to believe that I am a man.
And therefore, following the rules of logical inference, we have evidence to believe the conclusion: that I am mortal.
*side note – how logic works*
In order for a conclusion to logically follow from an argument, the argument must be both valid and sound. Not all arguments are sound and/or valid. An argument is valid only when its form follows the rules of logic (does not commit a logical fallacy). An argument is sound when it is valid and all of its premises are true.
An argument is a collection of truth-bearers that when taken to their logical conclusion, give evidence for a particular conclusion. If there is good evidence to accept the premises, then there is good evidence to accept the conclusion.
Take the syllogism offered earlier.
1. All men are mortal.
2. Elijah is a man.
3. Therefore, Elijah is mortal.
Wouldn’t you say that you now have evidence that I (Elijah) am mortal? Or do you still have to kill me (or wait for me to die) to know that I am mortal? I think you have good evidence to believe that I am mortal, wholly apart from killing me.
Evidence can be defined as the available body of facts or information which tends to prove or disprove something…
An argument can be defined as a collection of truth-bearing statements, reasons or facts used in support of an idea, theory or belief.
Then it seems reasonable to conclude that when an argument is both valid and sound, it becomes evidence for a particular conclusion. So is an argument actually evidence?
It would seem that the answer is… yes.
Evidence is used in justification for certain truth-bearing (can be true or false) propositions. An argument is a series of truth-bearing propositions, logically leading to a conclusion. If the premises of an argument are justified by evidence, and the argument is both valid and sound, the conclusion logically follows.
That logical conclusion from the evidence is also evidence for a certain conclusion. So, an argument is evidence. However, this is not meant to be a bifurcation between the concepts. Arguments and evidence are interdependent upon each other.
Have some thoughts or criticisms? Leave them in the comment section below 🙂