The Left Angle Cross of Upheaval is named for Gate 18 and Gate 17. Human Design reads Gate 18, from Hexagram 18, Work on the Decayed, sitting in the Spleen, as corrective instinct, an alertness to what is flawed and could be set right; and Gate 17, from Hexagram 17, Following, sitting in the Ajna, as the forming of opinions, logical viewpoints that want to be organised and offered to others. It belongs to the Left Angle family, read as transpersonal, a direction practitioners describe as answering less to personal choice than to what circumstance hands the individual.
Its design half is Gate 39 and Gate 38. Gate 39 sits in the Root and is read as provocation, the pressure that stirs feeling in other people; it pairs with Gate 55 in the channel of Emoting. Gate 38 sits in the Root and is read as the fighter, the drive to oppose and the need for something worth opposing; it pairs with Gate 28 in the channel of Struggle.
So a chart carrying this cross corrects flaws and offers opinions on its surface, while beneath it a provoking pressure answers to a fighter's need for a cause. The same four gates also underlie the Cross of Opinions and the Cross of Correction, and this cross's own reversal is the Left Angle Cross of Upheaval. Both hexagrams are old texts; pairing them this way as a life direction dates from the system's founding in 1987.