Regular visitors to the forum have probably seen this already, so I apologise for essentially quoting myself, but this is a subject I like discussing.
I see Dukat as having a very infantile ego, essentially a little boy's ego in a man's body. It's incomplete and vulnerable, dependent on others to validate it, and it's also very selfish, as an infant naturally is. Everything Dukat does is about earning approval; in a sense, earning love. Dukat, I think, needs reinforcement from others, and in his case that's dangerous because he also
failed to make the transition to genuine empathy with others. Empathy as I see it isn't just about the similarity between sapient beings, it's about the differences too - it requires respecting the distance as much as the connection. An infant, of course, eventually learns that other people are alien, that they're the centre of their own worlds just as he or she is the centre of their own. Dukat, I think, in some way still doesn't quite grasp this. How and why he's like that I couldn't say. But my idea of the character is that he's still the undisputed centre of his universe and, as far as he's concerned, everyone else orbits him. Basically, there's two
ways in which he strikes me as very infantile: his need to have his worth reinforced by others, combined with lack of true empathic understanding. I think it leads to the delusional idea that other people exist to validate him. His ego must be fed, and they must do it.
I get the sense that, ultimately, Dukat sees everyone and everything else as props in his own life. Their job is to reinforce his ego and let him know that he's a heroic and noble person, either by supporting him (for example, Ziyal and Damar) or antagonizing him "unfairly" (like Kira and Weyoun). It's no wonder that when he went mad in season six he had to create illusionary Damars, Kiras and Weyouns when he lost the real ones, because Dukat needs the reinforcement, then more than ever. That's what other people are for; they either feed his ego directly or they justify a sense of persecution and misunderstanding that allows Dukat to be the tragic hero of his own story.
I think Dukat wants to be seen as "noble", as far as his own child-like sense of the noble can carry him. And he surrounds himself with people to reinforce that illusion - Ziyal the blindly adoring daughter, Damar the lieutenant who is loyal but non-threatening (too unimaginative to challenge Dukat's position, yet ultimately more than the "typical" Cardassian military thug - he's intelligent enough to appreciate
Dukat), comfort women who will respond to Dukat's "generosity"
if only because they know they're trapped and it could be far worse. The same, I assume, motivated his move to abolish child labour when he was in command of Terok Nor – he expected the Bajorans to recognize his “nobility” and love him for it.
I also think Cardassia itself is something similar, a piece in his fantasy to feed his sense of selfish identity. If daughters, comfort women and lieutenants fulfilled his need to be the noble, benevolent master (again, to the extent that he understands "noble", which is through the prism of a child-like selfishness), then Cardassia fulfilled his need to be the servant. In his own mind, he's a good son to Cardassia, just as he's a good patriarch to his extended Cardassian/Bajoran community-family. Ultimately, though, he's every bit as disloyal a son as he is an abusive patriarch - both roles are ultimately to fuel his own need to experience a sense of his great worth.
And the tragedy of Dukat, as I see it, is that due to his inability to truly see perspectives other than his own, he never, ever grasped an opportunity to actually become a better person. He always chose to pretend to himself that he was great, and get others to tell him he was, rather than trying to become great. He's completely trapped in his own lie. His mind is yoked to his runaway ego, which needs reinforcement or he'll fall apart. As I often put it: Weyoun has the Founders, but Dukat is his own Founder.
I always try to explain Dukat in terms of season six, because I think any unified theory of the character has to explain his descent into madness and subsequent obsession with the pah-wraiths in terms of the man he'd been prior to that, rather than treating "mad Dukat" as a different person (whether the writers had a unified or sensible view of the character is open to debate, I suppose). As I see it, at the beginning of season six Dukat is at his height, because everything is fully safe and controlled with him at the centre. But then the universe crashes down when he loses Terok Nor again, along with Ziyal and (in a way) Damar. The loyal lieutenant can't shoot the pet daughter and I can't lose my war and my empire, that just can't happen! And Dukat ended up obsessed with taking down Sisko, who is - shock and horror - a challenger. I honestly think the reason Dukat fixates on Sisko (something other fans often say makes little sense) is because Sisko is the only other person Dukat actually truly recognizes
as another person. And that's because Sisko can't orbit Dukat like everyone else is made to, because he's a rival for Dukat's position. Sisko is in Dukat's office, he has Kira's respect, the Bajorans' respect, he's a strong, noble military leader, a loving father, victorious in battle - Dukat has encountered a rival. And this universe isn't big enough for both of them, because the universe is supposed to revolve around Dukat, not this usurper.