system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40K] How much compassion remains in a Space Marine after augmentation?

The Space Marines are loyal soldiers of the Imperium, walking to their deaths with a smile on their face, as was programmed into them. However, how far does this programming go? With some chapters like the Salamanders, they contain enough compassion to go out of their way to defend civilians, even at great risk to themselves. This would seem to contradict the "Remorseless killing machine" personality they are know for. Likewise, the Marines have basically been programmed to kill anyone for a hint of Heresy, but the Space Wolves where willing to wage war on the Inquisition to protect those the Inquisition saw as Heretical. 

So, to what extent is a Space Marines personality altered by augments?
gpt
First things first: there's not really a standard "Space Marine culture" beyond some broad tenants (loyalty to the Imperium and Emperor, martial honor, etc.) Each Chapter has a unique culture stemming from its history, homeworld, and general temperament of its Marines - which includes views on ordinary men and the ethics of civilian casualties. Chapters that care about civilian casualties tend to be more involved with the general population of their homeworld (like the Salamanders, Ultramarines, Space Wolves). And even within Chapters, individual Marines often disagree and can vehemently argue amongst themselves.

What this is getting at is that while Space Marines are well indoctrinated into their Chapter's tactical, ethical, moral and spiritual tenants, the idea of a Space Marine as a remorseless or unfeeling killing machine is not true. For all their strength of mind and body, they're ultimately still men; they from friendships, have disagreements, and form their own opinions. From the number of Astartes who have told their Battle-Brothers, commanding officers, and the frigging Inquisition itself to fuck right off, they're not really "programmed" so much as "indoctrinated."