The flute is not an instrument that has a good moral effectöit is too exciting.

-Aristotle
c.330  BC  Politics.

Nature is but a name for an effect, Whose cause is God.

-Cowper,William
  The Task, bk.6,'The Winter  Walk at Noon', l.223.

What I really like is minimum effort for maximum effect. Like with Picasso's Bull's Headöa bike seat and handlebars.

-Hirst, Damien
  In the Idler,10  Jul.

   We have no other notion of cause and effect, but that of certain objects, which have been always conjoined together, and whichinall past instanceshavebeenfound inseparable.

-Humboldt, Alexander, Baron von
  A  Treatise of Human Nature, bk.1, pt.3, section 6.

Inmyopinionpainting should be considered excellent in proportion as it approaches the effect of relief, while relief should be considered bad in proportion as it approaches the effect of painting.

-Michelangelo full name Michelangelo Buonarroti
Quoted in Robert  J Clements (ed) Michelangelo:  A Self-Portrait (1968).

Amid the wreck and the misery of nations it is our just exaltation that we have continued superior to all that ambition or despotism could effect; and our still higher exaltation ought to be that we provide not only for our own safety but hold out a prospect for nations now bending under the yoke of tyranny of what the exertions of a free people can effect.

-Pitt,William known as  theYounger
  Speech to the House of Commons, 25 Apr.

The poet must be free to love or hate as the spirit moves him, freeto change, freeto be a chameleon, freetobe an enfant terrible. He must above all never worry about his effect on other people.Power requires that one do just that all the time. Power requires that the inner person never be unmasked.No, we poetshavetogo naked. And since this is so, it is better that we stay private people; a naked public person would be rather ridiculous, what?

-Sarton, May
  Hilary Stevens. Mrs Stevens Hears the Mermaids Singing, pt.2.

The great instrument of moral good is the imagination; and poetryadministers to the effect byacting on the cause.

-Shelley, Percy Bysshe
A Defence of Poetry.

The difficulty with humorists is that they will mix what they believe with what they don't; whichever seems likelier to win an effect.

-Updike,John Hoyer
  Rabbit, Run.