What makes people irrational thinkers?

[LadyForCamus]

The uses of the word contingency that @polymath257 described (a feature of logical deductions, an aspect of causality) are connotations. They all participate in a simple concept. The word contingent has sufficient definition when used properly to indicate dependence on something else. The opposite of contingent is necessary. That said, once a disagreement reaches the point of bickering over semantics, the discussion ceases to be interesting.

To me, this simply pushes the issue back one step: 'dependence' in what sense?  Does everything 'depend' on something? Can something depend only on itself? Can something 'depend' on nothing at all?

Does logic, for example, 'depend' on anything else? Does math? Does the universe?

In all of these cases, I see nothing to suggest there is a dependency on anything else, but there are claims that, for example, the universe is not 'necessary', which goes directly against the do of 'necessary' as 'not contingent'.

So, in what sense is the universe contingent? How do you conclude it has to 'depend' on something else?

The conflation of the different notions leads to very bad reasoning and confused logic. By using vague notions, it papers over problems in the reasoning that reveal massive holes in the argument.

And therein lies a huge problem (as I see it) with using logic to argue god into existence. A logical argument is only as useful as truth of its premises. Perhaps it is a category error to demand physical evidence for god, but it is certainly the responsibility of the theist to provide sufficient evidence for the grand and sweeping assertions about the nature of physical reality made in arguments like the 5W and other ontological arguments. These arguments directly refer to alleged truths about our physical reality and therefore require adequate evidential support before they can be reasonably accepted. That’s why definitions are imperative. It’s not an issue of semantics, it’s an issue of accuracy.