Politics, as a practice, whatever its professions, has always been the systematic organization of hatreds.

-Adams, Henry Brooks
  The Education of Henry  Adams, ch.1.

Medical men all over the world having merely entered into a tacit agreement to call all sorts of maladies people are liable to, in cold weather, by one name; so that one sort of treatment may serve for all, and their practice thereby be greatly simplified.

-Carlyle,Jane Baillie ne¤  e Jane Baillie Welsh
  Letter to  John Welsh, 4 Mar.

The fact is, that there was considerable difficulty in inducing Oliver to take upon himself the office of respirationöa troublesome practice, but one which custom has rendered necessary to our easy existence; and for some time he lay gasping on a little flock mattress, rather unequally poised between this world and the next: the balance being decidedly in favour of the latter. Now, if during this brief period,Oliver had been surrounded by careful grandmothers, anxious aunts, experienced nurses, and doctors of profound wisdom, he would most inevitably and indubitably have been killed in no time.

-Dickens, CharlesJohn Huffam
^9  Oliver Twist, ch.1.

Writing a novel does not become easier with practice.

-Greene, (Henry) Graham
  Ways of Escape, ch.5.

An economist is someone who, when he finds something which works in practice, wonders if it will work in theory.

-Heller,Walter Wolfgang
   Attributed.

Wie manches wu«  rde in derTheorie unwidersprechlich scheinen, wenn es dem Genie nicht gelungen w a« re, das Widerspiel durch dieTat zu erweisen. How many things would have appeared incontestable in theory if genius had not proved them wrong in practice. Levant

-Lessing, Gotthold Ephraim
  Laokoon: an essay upon the limits of painting and poetry, pt.4.

But even Archimedes was not free from the prevailing notion that geometry was degraded by being employed to produce anything useful. It was with difficulty that he was induced to stoop from speculation to practice. He was half ashamed of those inventions which were the wonder of hostile nations, and always spoke of them slightingly as mere amusements, as trifles in which a mathematician might be suffered to relax his mind after intense application to the higher parts of his science.

-1st Baron
  'Basil Montagu's edition of  The Works of Francis Bacon, Lord Chancellor of England ', in the Edinburgh Review,  Jul.

The Socialist papers†came out full tothethroat of well- printed matter†admirable and straightforward expositions of the doctrines and practice of Socialism, free from hasteand spiteand hard words†with a kind of May-day freshness amidst the worryand terror of the moment.

-Morris,William
  News from Nowhere.

He said that there is no art without practice, and no practice without art.

-Protagoras
Fragment quoted in H Diels andW Kranz (eds) Die Fragmente der Vorsokratiker, vol.2 (1952), 268, no.10.

In a civil war, a general must knowöand I'm afraid it's a thing rather of instinct than of practiceöhe must know exactly when to move over to the other side.

-Reed, Henry
  Not a DrumWas Heard:TheWar Memoirs of General Gland, unpublished radio play.

As every teacher, like every drill-sergeant or animal trainer, knows in his practice, teaching and training have virtually not yet begun, so long as the pupil istoo young, too stupid, too scared or too sulky to respondöand to respond is not just to yield.Where there is a modicum of alacrity, interest or anyhow docility in the pupil, where he tries, however faintheartedly, to get things right rather than awkward, where, even, he registers even a slight contempt for the poor performances of others, of chagrin at his own, pleasure at his own successes and envy of those of others, then he is, in however slight a degree, co-operating and so self-moving.

-Ryle, Gilbert
Quoted in R S Peters (ed) The Concept of Education (1966), ch.7.

To sum up: your father, whom you love, dies, you are his heir, you come back to find that hardly was the corpse cold before his younger brother popped on to histhrone and into his sheets, thereby offending both legal and natural practice. Now why exactlyare you behaving in this extraordinary manner.

-Stoppard, SirTom originally Tom Straussler
  To Hamlet. Rosecrantz and Guildenstern are Dead, act1.

   For as concerning football playing, I protest unto you it may be rather called a friendly kind of fight than a play or recreation, a bloody or murmuring practice than a fellowly sport or pastime.

-Stubbes, Philip
  Anatomie of Abuses in the Realme of England.