The key to this dilemma is the notion of what constitutes 'evidence'. As skeptics often use the word, it creates some problems which could be avoided if we really considered what the term is understood to mean.
'Evidence' is a subjective quality we apply to any observation. This quality connects that observation with concepts we accept describe the universe. As it is subjective, it's possible that an observation I find to be evidence is not considered evidence to somebody else.
This lies at the heart of a good majority of arguments between skeptics and believers. What constitutes 'evidence' for an idea is a bit like arguing whether a sunset truly is beautiful.
Now, for evidence to be considered useful, we could apply a set of criteria to it. These criteria are marked against a set of values we deem to be important (whether we put a lot of consideration into them or not). Some of us will have values that attempt to adhere to logic, internal consistency and value the opinions of others who share the same values. Others might value evidence according to how well it reflects a more supernatural notion, or reflects personal sentiments and emotional qualities, such as intuition. One set of values can be demonstrated to be more useful in making predictions that have a relatively high chance at eventuating.
Telling somebody they have no evidence is therefore not only going to encourage them to not listen to you, it's also wrong. What is more truthful is that their evidence is based on values that are less likely to prove useful in making decisions about objective events.
The question of ignoring evidence vs. refusing to believe it seems to be a fine line between the skeptic and the believer. I'm sure I could think of additional examples, maybe climate change and continuing to buy fossil fuels vs. an alternative, or that vegetarian lifestyles could be better for the planet in general? I think there are many cases where we as skeptics might accept the evidence for something, but simply not change or modify our lifestyles to suit the new evidence for something.
How we use observations and interpret them as evidence is one thing. How we change our behaviour in response to it depends again on that hierarchy of values.
Look at it this way - I'm the sort of guy who likes a cigarette when I'm out having a few drinks. I don't ever smoke otherwise, and even then, I'll only light up two or three cigarettes once every six months or so.
The observations I recognise as evidence for the harm smoking does are normally enough for me to not take it up as a habit (not to mention the other side-effects). Those observations don't disappear on the evenings I do have a cigarette, nor are they no longer evidential. They simply are lower down the list, with other factors taking precedence. That doesn't mean I ignore the evidence, as such. It does mean there are other needs which my brain sees as more important during those moments.
This translates to most situations. You might value money, yet if you were starving, you'd happily part with your cash for a morsel to chew on. You wouldn't argue that there is no evidence that it's important to save - you'd just have more pressing arguments changing the context of the argument.
Athon
