johnson wrote:purpose is the product of an intelligence.

The theist will say that purpose is evident in parts of nature. Therefore, it indicates a responsible intelligence, since purpose is the product of intelligence. Saying that it's an illusion(which mostly captures what is happening) sounds like a conspiracy theory to them. How would you explain to them that nature creates things which appear to have purpose created by intelligence?

Interbane:
The theist will say that purpose is evident in parts of nature. Therefore, it indicates a responsible intelligence, since purpose is the product of intelligence. Saying that it's an illusion(which mostly captures what is happening) sounds like a conspiracy theory to them. How would you explain to them that nature creates things which appear to have purpose created by intelligence?

This is the tough part. Things really are complicated and difficult to understand. Well, lets say, counter-intuitive. We have a number of short-cut understandings that give us an immediate picture which we can use to manuever the world, but those are much less accurate than we imagine.

It's easy to say that out immune system's "purpose" is to fight disease. But it's not.

That's what our immune system ends up doing. It's an emergent property. There's a whole heck of a lot of disease that our immune system is totally inadequate to deal with.

That's because it isn't FOR "fighting disease". It developed in tandem with certain cells from outside our bodies which cause harm. Those organisms which had ways of making it difficult for those foreign cells to thrive had better survival rates, and using those survivors as a jumping off point you get better and better survivability against certain foreign bodies. But that doesn't mean our immune system "fights disease". It sucks at repelling virus, proteons, cancers, genetic disease, and deterioration from external sources, and some of these it doesn't attack at all.

It's more accurate to describe natural systems in terms of "that's what it does" rather than "that's what it's for."

I don't know of an easy way to distill that yet without typing an enormous amount of information. Even what i've typed is too long for the kind of snap understanding people crave. I typed all that knowing i was speaking to you. Knowing you already know it. And i still feel like it kinda needs more explaining. It's not susinct.

I don't know any way around it except to have people really dive into it themselves and get to know some physics and biology.