[hxa7241]

What is this 'theory' Naur talks of? It is not a nebulous feeling or sensation, it is something complex, articulate -- something 'built'. But how can something with logical structure be at the same time inexpressible? There is a contradiction lurking there.

Imagine you are 'building' one of these 'theories', to make some software. How do you know it is correct? The only way is by testing it against the world, and to do that it must be expressed. And any part that is not expressible cannot, for that reason, be a usable part of the 'theory'. (It is more basic really: a 'thing' in your mind, that cannot be expressed, is not really a 'thing' at all.)

The reason programmers are not simple replaceable resources is not because some kind of 'theory' thing is not expressible, but because making software requires certain significant practicalities of effort, knowledge, and skill.