In many ways Space Marines are both more and less than the teeming mass of humanity – physically they appear to be perfect, if enlarged, versions of common humanity and their intellect, whilst necessarily focused is formidable and yet...

They lack or at the very least have modified versions of some of the baser emotions – such as Love and Fear. In addition, having been taken from the normal population at a young age, they usually have problems relating to normal human wants and needs. They mix and train with other superhuman giants and often the only humans they see are Chapter serfs or vassals.

Powerful emotions are not unknown to Space Marines... they feel good honest Hatred, often cited as one of the foundation stones of the Imperium and although “They shall know no fear” it is evident that they can feel intimidated and recognize superior opponents or untenable odds. Fear of Failure and the resulting Shame can be damaging to the mental state of a Marine and even a whole chapter has been committed to rash and foolish decisions to regain their honour or make amends. Pride in their work, their actions and the deeds of their fellows and Chapter in general are always a powerful force to a Marine but can make it difficult for them to accept advice or criticism from “lesser beings.”

Friendship and Brotherhood is ingrained into them and the bonds between squad mates are often very powerful, lasting as they may for decades. Perhaps given their Spartan style existence this is another reason for the Chem Geld? Anger is an emotion to be used and unleashed upon an enemy – although this can fester and gnaw at a Marine, especially when they have no outlet, and a enraged Marine can cause as many problems to his brothers as as to his enemies.

Faith varies in its nature from Chapter to Chapter; some, like the Black Templars are devotees, but to the irritation of the Ecclesiarchy, the majority of Space Marines do not follow the Imperial Cult – many within that organization actually consider the belief of many Chapters heresy whilst many of the Chapters consider the Imperial Cult as little more than fawning superstitions much removed from the reality of the Emperor and his Primarchs.

Other emotions are less important to a Marine – compassion and mercy are neither encouraged nor natural to a Marine – they have difficulty understanding what it is like to be as weak as a human. It is true that Compassion and Mercy in the Imperium is often best expressed by the following phrase:

In short they are not mere killing machines, they feel and think, perhaps differently – they hurt and consider the world around them – especially as they age. Humor is not unknown – at least in many chapters, and decades, even centuries of life can provide a unique insight into the workings of the Universe – or contribute to make even a Space Marine become insular and callous. Each marine, like any man, is different, retaining elements of their original personality after their transformation into a Space Marine.

Like the men who become Marines, every Chapter is very different, and even successor Chapters can be strange and uncanny places to Marines – as unsettling as the most bizarre Imperial world. In keeping with this diversity, each Chapter chooses the inheritors of their heritage in different ways – some take those that are about to die in battle – like the Space Wolves, others set great tasks to select the most worthy – like the Blood Angels. The more divergent from the Codex Astartes the Chapter is, the more bizarre or arcane the rituals of rebirth into the Chapter can be. Like any form of childhood, these are powerful periods in a Marine’s life and help to transform the remaining personality into something more fitting to the culture of the Chapter.

Some Chapters consider the past life of the neophyte is irrelevant and to be erased – treating their ascension into the ranks of Space Marines as a complete rebirth. They require only the skills of the supplicant and will reshape his mind and beliefs to their own requirements. Yet the majority of Marines retain memories, however faint, of their former life.