Negative Capability; that is, when a man is capable of being in uncertainties, mysteries, doubts, without any irritable reaching after fact and reason.

-Keats,John
  Letter to G and T Keats, 21 Dec.

Electricity is of two kinds, positive and negative. The difference is, I presume, that one comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it.

-Leacock, Stephen Butler
  Literary Lapses,'A Manual of Education'.

Great Negative, how vainly would the wise Enquire, define, distinguish, teach, devise, Didst thou not stand to point their blind Philosophies.

-Rochester,JohnWilmot, 2nd Earl of
c.1673  'Upon Nothing', stanza10 (published1679).

Alle Befriedigung, oder was man gemeinhin Glu«  ck nennt, ist eigentlich und wesentlich immer nur negativ und durchaus nie positiv. All satisfaction, or what iscommonlycalled happiness, is really and essentially always negative only, and never positive.

-Schopenhauer, Arthur
  DieWelt alsWille undVorstellung (TheWorld asWill and Representation), vol.1, bk.4, ch.58 (translated by E F J Payne).

A good many times I have been present at gatherings of people who†are thought highly educated and who have†been expressing their incredulityat the illiteracy of scientists.Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative.

-Snow, C(harles) P(ercy), 1st Baron
  TheTwo Cultures, Rede Lecture, ch.1.