You'd be surprised how often we don't really know whether it was designed or not. A lot of natural processes can make objects look like they were designed. Oldest example in the book are of course rocks that look like faces, but were never touched by human tools. Interpreting such rocks as man-made would be false, but not illogical if you don't do more research.



You still haven't responded to why it must be designed. Complexity says nothing about whether it must be designed or not, in fact.. most inventions are actually amazingly simple. Aren't those designed too?



We're not overlooking the complexity at all, we're just convinced it's not a given fact that everything that must be complex must have been designed. In fact, you're overlooking how evolution shaped us into what we are now. You could call this a passive design (evolution has no aim), but it doesn't mean some higher being must have designed us.

In fact, it makes no sense, as it would mean he created a universe, gave it a kick and billions of years later we came into existence. Doesn't sound very plausible to me at all, especially knowing how evolution is a process that still goes on until this very day. We are by far not yet the 'end product', in fact there's no such thing as an 'end product'.



Our logic is based upon knowledge and we're not assuming weird, physically impossible things though.



We can talk to the developers, we can understand the tools involved, we have some sight into what has been developed when..... all that in itself is more than enough proof of it being designed.

Remember... we can't talk to God, we don't have a clue what he could possibly have used to create anything, nor do we really have a good view onto when he created what (after all, most creationists believe our earth isn't billions of years old, which leads to an obvious problem following this kind of logic.)



That's exactly true for humans. No human nor designer holds a copyright on our species.