Here is the full list of all 20 Disjunction achievements.
Knock out an investigating enemy while invisible
Complete a level without alerting any enemies
Complete a level without taking damage
Complete a level without using any abilities
Complete a level without killing anybody
Complete a level having killed everyone
Hit the same enemy with a smoke grenade, a shock bolt, and your baton
Kill two enemies with one shotgun blast
Collect all the Upgrade Kits in the game
Collect all the Lore items in the game
Spare Mara Bishop
Kill Mara Bishop
Side with Mara Bishop
Accept Bribe from Mara Bishop
Complete the game without killing anybody
Complete the game having killed everyone
Beat the final level as Frank
Beat the final level as Joe
Beat the final level as Spider
Beat the game