a) Retain aka re (to respond) tain/ten (to stretch) aka responding to being (life) stretched (inception towards death)...that's the struggle of yisra-el.

b) Upright aka up (towards) right/reg (to move in a straight line) aka life being moved from inception towards death in a straight line, which once again implies the struggle of yisra-el.

c) Gentiles are tricked to ignore analysis for synthesis, hence accepting "retain" (to keep in possession) and "upright" (erect; not bent or curved) as definitions/meaning/truth.

Being implies solid (life) within fluid (inception towards death)...a jew tempts gentiles to solidify their minds with artifice, while ignoring natural liquidity or as stated in your link..."to become rigid from the retention of liquidity"

Suggested information tempts one to ignore perceivable inspiration...the former tempts one to hold onto, while the latter moves through one, and cannot be held onto.

A jew (singular) thinks fluid; gentiles (plural) think solid...fluid destroys solid unless resisted.

tl;dr: Thanks for the link.