# Two Tests With Two Morals

These tests are interesting because it illustrates two separate points
quite well. First, let's take the tests, then I'll draw the morals
for you. I first encountered the scheme used here in Daniel Dennett's
book "Darwin's Dangerous Idea" (which I highly recommend), and I
present it almost unchanged:

## Test Number One

You have a set of cards before you. Each card has a letter on one
side, and a number on the other.

----- ----- ----- -----
| D | | F | | 3 | | 7 |
----- ----- ----- -----

Now, let's say there's a condition that you're asked to check for. The
condition is, *"If there's a D on one side of the card, then there's
a 3 on the other side."* Which of the above cards do you need to
flip over to see if that condition is met? Take your time, reason it
out.

I won't tell you the answer yet. For now, let's move on to the second test.