A mistaken plausible line of reasoning

Here is Eric Drexler:

A scientist recently remarked to me that molecular modeling techniques cannot accurately predict the mechanical properties of typical polymers, even one as simple as polyethylene, a hydrocarbon consisting of long chains of –(CH₂)– units. He was, I think, suggesting that molecular modeling may tell us little about molecular technologies based on structures that would be far more complex.

It’s important to understand why this plausible line of reasoning is mistaken.

Take a look!