A New Yorker  weblog post from yesterday, All Souls' Day—

"As the mathematician Terence Tao has written,
math study has three stages:
the 'pre-rigorous,' in which basic rules are learned,
the theoretical 'rigorous' stage, and, last and most intriguing,
'the post-rigorous,' in which intuition suddenly starts to play a part."

Related material— 

Rigor  in a Log24 post of Sunday evening, May 25, 2008: "Hall of Mirrors."

Note in that post the tesseract  viewed as the lattice of
the 16 subsets of a 4-element set.

Some further material related to tesseracts and time, in three stages
(roughly corresponding to Tao's, but not in chronological order): 

  1. Bakhtin, 
  2. Spaces as Hypercubes, and 
  3. Pindar.

See also a recent Log24 post on remarks from Four Quartets .

(The vertices of a tesseract form, in various natural ways, four quartets.)