The Fifth of the Five Ways

[BrianSoddingBoru4]

Thomist: The Teleological Argument is actually about the per se cause of the tendency of each creature to an end. The origin of species via evolution is completely irrelevant, as evolution is a per accidens cause.

I answer that,

Natural selection and deep time results in the simulacrum of design. Aquatic mammals resemble fish because their form, after many reproductive iterations, is optimal for their environment. A valid argument from design must first rule out whether the design is merely apparent.

Your response to the Thomist is a complete non sequitur. 

If you're interested in understanding what the Fifth Way really says (as opposed to whatever it is you're arguing against) you can read Aquinas: A Beginner's Guide by Edward Feser. He does a good job of explaining how the Fifth Way is not like an intelligent design argument, or Paley's watchmaker argument. 

It looks as though the guy you were talking to understood it better than you. If you ask him he may be willing to explain it to you.

Of COURSE the Fifth Way is an intelligent design argument. Instead of Feser, try reading Aquinas - he said it was an intelligent design argument.

We see that things which lack knowledge, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that they achieve their end, not fortuitously, but designedly. Now whatever lacks knowledge cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God (Aquinas, Summa Theologica, Article 3, Question 2).

(the refutation of the Fifth Way is painfully simple, but beyond the scope of this thread)

Boru