Full Idea
It is only rational beings who can be attentive without a motive; only rational beings who can be interested in that in which they have no interest.
Gist of Idea
Only rational beings are attentive without motive or concern
Source
Roger Scruton (Laughter [1982], §12)
Book Reference
Scruton,Roger: 'The Aesthetic Understanding' [Methuen 1983], p.165
A Reaction
Rational beings make long term plans, so they cannot prejudge which things may turn out to be of interest to them. Scruton (a Kantian) makes it sound a little loftier than it actually is.