Rationality Quotes January 2014

Rules:

Please post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

Rules:

Please post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

I also found it hard. For the benefit of the next person, here is a rewritten version:

If you don't know how to unknow things, then you also don't know how to know things.

Or, passing to the contrapositive,

If you know how to know things, then you also know how to unknow things.

Or,

One who knows how to know things must also know how to unknow things.

My first attempt was

Indeed he (knows not) how to (know who (knows not also (how to unknow)))

Meaning

This person does not know how to distinguish between those who know how to unknow, and those that cannot.

Now my brain doesn't recognize "know" as a word ...

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