“But such is the nature of the human mind, that it always lays hold on every mind that approaches it; and as it is wonderfully fortified by an unanimity of sentiments, so is it shocked and disturbed by any contrariety.”

Introduction : Woman as Other http://books.google.com/books?id=kUW0AAAAIAAJ&q=%22It+is+doubtless+impossible+to+approach+any+human+problems+with+a+mind+free+from+bias%22&pg=PA20#v=onepage
The Second Sex (1949)

Letter 2
Letters on Logic: Especially Democratic-Proletarian Logic (1906)

Source: Mary Shelley's Frankenstein

Aphorism 52
Novum Organum (1620), Book II

As quoted in Cosmopolitan (December 1892).
Context: A so-called magician, more than a poet, must be born with a peculiar aptitude for the calling. He must first of all possess a mind of contrarieties, quick to grasp the possibilities of seemingly producing the most opposite effects from the most natural causes. He must be original and quick-witted, never to be taken unawares. He must possess, in no small degree, a knowledge of the exact sciences, and he must spend a lifetime in practice, for in the profession its emoluments come very slowly. All this is discouraging enough, but this is not all. The magician must expect the exposure of his tricks sooner or later, and see what it has required long months of study and time to perfect dissolved in an hour. The very best illusions of the best magicians of a few years ago are now the common property of traveling showmen at country fairs. I might instance the mirror illusions of Houdin; the cabinet trick of the Davenport Brothers, and the second sight of Heller — all the baffling puzzles of the days in which the respective magicians mentioned lived. All this is not a pleasant prospective picture for the aspirant for the honors of the magician.

The Life of Gray
Lives of the English Poets (1779–81)

Short story, "The break", p.25
Short Stories, The Great Profundo and Other Stories (1987)