What does this saying mean?

Question

I encounter an incomprehensible saying:

Except as a man handled an axe*, he had no way of knowing a fool.

while reading this tutorial.

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*I wanted to add a mark here which means the possible error derives from the source

Answer 1

This is a quote from Spenser:

"Men of the wood and lumberjacks,
they judged me by the appropriate tool.
Except as a fellow handled an axe
they had no way of knowing a fool."

I take it to mean that people can judge you only in terms of things that they understand.

Answer 2

The speaker is saying that lumberjacks had no way to judge a man's importance or value or capabilities except by observing how he handled an axe.