[farginay]

I think it is fairer to say that tests can specify a system but not to the extent that you personally want to.

[colanderman]

I don't know; I'd be wary of working with any architect who handed me a list of test cases as a specification. What if he/she left out important edge cases, which I extrapolate incorrectly? How am I to infer that the absence of a test case means "not specified" vs. "specified to be the extrapolation of other test cases"?

That's kind of like saying that a coder who can only write pseudocode can code a system, but not to the extent that I personally want him/her to.

[davidw]

I'd be wary of comparing programming to architecture.

[farginay]

Be wary of an architect who hands you anything and tells you to implement it. Real architects talk to you and sit down and write code with you.