Cylons are not 'Evil' per-se, they just view things through different lights. This section attempts to explain Cylon motivations and how they see things.

To the Colonials, what motivate the Cylons is a complete mystery, and even to this day, they still do not know drives them. Some races they exterminate, some races they enslave and some they just leave alone. Colonials would love to know why.

To the Cylons though, it is a very simple story. Humans (and some other races) are not only a threat to the Cylon way of life, but also a threat to the Universe itself.

Cylons see themselves as the 'caretakers' of the universe. They value an ordered society and an ordered galaxy. Some races can fit within this order quite nicely, and these races are not harmed. In fact, the majority of them are probably not even aware that the Cylons exist. One of the main reasons for this, is that the Cylons do not really care what races do to their own planets and themselves - provided they keep their actions to their own planet. Once a race develops space flight however, then their potential for trouble increases amazingly, and suddenly the Cylons have to keep the race under surveillance. If the race is good and keeps it is exploits of other planets down to a minimum, and if the race sticks to some sort of Cylon order (usually without knowing it), then they can be allowed to continue to exist under their own control.

Some races need a slight bit of guidance to be allowed to continue. These races will be contacted by the Cylons and spared provided they adhere to Cylon rule. Other races though, cannot submit, or will not. These races must be removed. There is no malice involved by the Cylons, they do not care what merits an individual race has or has not got. They simply become a threat and must be removed. For the sake of the Cylon order, and also for the sake of the Universe.

Whilst exterminated races are destroyed like pests, they are not destroyed with any malice. Nor are they forgotten. The Cylons do keep records of all the races they have destroyed, and do keep artefacts and pieces of art from these races if they are deemed to be suitable examples of that races works. Thus, for example, you will still see the crystalline structures built by the Delphian Empire on Gamorray, just now inhabited by the Cylons.

Humans are unique amongst the races encountered by the Cylons. Other races have been easy to exterminate (the Delphian Empire, the Hasaris), or subjugate (the Ovions) or just watch. But the humans are different. And the Cylons do not know why. And this frightens them a bit, which is why there definitely must be no survivors. Humans have traits that the Cylons have long since abolished - individuality, freedom of speech being two main examples - and they are just too chaotic and unpredictable to be allowed to continue. Whilst most Cylons will have no thoughts about them, upper levels of IL Series and, it is rumoured, the Imperious Leader himself, actually have an emotion about the humans - hate. This is not good. Humans, as well as all their other traits, have the ability - through their presence alone, it would seem - to turn Cylon life upside down, and attack all fundamental beliefs from the top level down. This makes them extra dangerous.