Here's the new thread for posting quotes, with the usual rules:
- Please post all quotes separately, so that they can be voted up/down 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- Do not quote yourself
- Do not quote comments/posts on LW/OB
- No more than 5 quotes per person per monthly thread, please.
On the error of failing to appreciate your opponents' three-dimensionality:
Source: Milton Friedman, "Schools at Chicago," from The Indispensable Milton Friedman
H/T David Henderson at EconLog
Note: The final sentence of the passage, as presented by Henderson, is missing closing quotation marks. I have added them.
Of course, even in this case, you often cannot be very sure.