I think you hit the crux of the argument right there, DMTripper: It is natural to feel a little low sometimes. What are the highs if there are no lows? that's the tau.

However, I got very interested in this neurotoxicity issue.

"Doses of MDMA that produce neurotoxicity in lab animals have generally been considerably higher than a human user would normally take"
http://www.dancesafe.org...uginfo/neurotoxicity.php

and with the general MDMA content of tablets (~100mg) [IF MDMA AT ALL]
that would put the "safe dose" at about 1.5 pills per person.