Maybe I'm just stupid or there maybe a bug in my version. I'm able to get to Crete (on most paths...haven't tried them all yet) have both sun and moonstone but when I align them up according to Plato's Dialogues nothing happens. I'm pretty sure that I'm doing it right. Anyone else having this problem?

From experience, sometimes, when it seems like you've aligned the stones exactly like Plato's Lost Dialogue told you to, and the door still refuses to open, the trick is to rotate all stones 90°, 180° or 270° in one direction and try again.

Thanks. This seems to do the trick.

Ok, I am answering a very old post. I had the same problem.
Thing is, not all items align with the horns. The first stone paragraph tells you how to align the first disc. The second one tells you how to align the second disc with the first (Moon vs Sun) and the third paragraph tells you how to align the third disc with the second disc. So I had
"If morning light warmed the tall horns"
"Darkest night healed by full moon"
"Moon full of beauty lighting the city"
Solution:
1) Align rising sun with horns
2) Align Full moon with Darkness
3) Align City with Full moon.
Press spindle.