Satan's despair is absolute because Satan, as pure spirit, is pure consciousness, and for Satan (and all men in his predicament) every increase in consciousness is an increase in despair.

The deepest form of despair is to choose to be another than himself.

The most common despair is...not choosing, or willing, to be oneself...[but] the deepest form of despair is to choose to be another than oneself.

Sin is: before God, or with the conception of God, in despair not to will to be oneself, or in despair to will to be oneself. Thus sin is intensified weakness or intensified defiance: sin is the intensification of despair. The emphasis is on before God, or with a conception of God; it is the conception of God that makes sin dialectically, ethically, and religiously what lawyers call 'aggravated' despair.

Only when it is a duty to love, only then is love eternally and happily secured against despair.