In Search of a Design Filter

My last post is not actually about William Paley, the design argument, or intelligent design. Rather, it is about the changing of intellectual fashion, and the subtle bullying that occurs when some refuse to accept the change. 

Just look at the level of vitriol directed against those who dare to defend the design argument (calling them "IDiots" for instance). Insults are never helpful. Another disturbing trend is the conflation of design with various taboo positions, especially "creationism". I assure you, Cicero and Averroes were not creationists. To learn what a creationist actually is, read Ron Numbers' historical treatment of this movement titled, aptly enough, The Creationists. Insults and the tendentious conflations do indeed border on intellectual bullying because they send the message "just shut up ya moron".

Okey dokey, with that done, we can get on to arguments. The design argument is inductive, and thus merely seeks to establish its conclusion as more plausible, reasonable or likely than the alternative. Does it succeed?

This brings us to the human genome which is appropriately called the blueprint of life as its more than three billion DNA base pairs carry a massive amount of information equivalent to a library of x many books. The question is simply whether it is reasonable to infer that the genome is the product of intention or, more robustly, whether it is more reasonable to infer this than the alternative that it is not.

Gaga has no time for this as he retorts (to my previous illustration which compared DNA to rocks carved like the Rosetta stone):

We *know* that people build watch-*ehm* Rosetta stones.
We *don't know* that people build strands of DNA.

The claim here seems to be that we must first see a type of thing being constructed by an intelligence before we can infer that any future examples we encounter were likewise constructed by an intelligence. Gaga later states this criterion as follows: "we know that people produce stuff like that."

Gaga also adds a second criterion. For design to be inferred the object or process must "show signs of an intervention." for instance, an arrowhead shows signs of intervention, but a skull does not. AnAtheist.Net echoes this criterion by referring to the "hallmarks of manufacturing" which are evident in the Rosetta stone but not in DNA.

So these are our two criteria that the critics use to deny the claim that it is more reasonable to infer DNA was designed than not: (1) we have no evidence that intelligence produces the type of thing that DNA is, and (2) DNA does not show evidence of manufacture, contrivance or intervention.

Before offering a critique of this proposed design filter, I would ask my critics to weigh in on my presentation of these criteria. Is this a correct summary? Are these taken to be the two necessary and sufficient criteria by which we legitimately infer design?