Critique of Judgement by Immanuel Kant Chapter 12 Page 4

But yet it involves causality, viz. of maintaining the state of the representation itself, and the exercise of the cognitive powers without further design. We linger over the contemplation of the beautiful, because this contemplation strengthens and reproduces itself, which is analogous to (though not of the same kind as) that lingering which takes place when a [physical] charm in the representation of the object repeatedly arouses the attention, the mind being passive.