What and How We Know
Dr. Trevor in Evenings with the Skeptics: Free Discussion on Free thinkers, pp. 34-5.
I come lastly to a third type of intellect, in which Twofold Truth presents itself in a moderate and altogether commendable shape; in which the disparity is not so much antagonistic as complementary, and the result of its functions is not disunion and hostility so much as a broad comprehensive solidarity. For our purpose we may call intellects of this class 'dual-sighted' or 'two- eyed.' ... This 'double-sighted man' is by no means the synonym of the nickname common in Puritan history, 'Mr. Facing-both-ways.' It rather implies the possession of faculties which enable the observer to see every object in the solid, substantial manner, in the full relief, and with the true perspective that pertain essentially to all double vision. It is the instinctive power and tendency to discern a specific object or a given truth not merely as it is in itself or in one of its prima facie aspects, but in its completeness as a whole and relatively to all its surroundings. We see this quality in the artist who simultaneously with the perception of an object also sees all its different phases as well as its relations to surrounding objects; or again in the general who apprehends by a single glance of his mental vision all the characteristics, bad as well as good, of a given position or military movement. So the philosophers I speak of catch every truth or doctrine, not in its simple and uniform, but in its complex biform or multiform aspect. They are men to whom every affirmation suggests, if only as a possibility, a negative; who intuitively meet every dogmatic pronouncement with an objection, just as a painter infers shadow from light. These are the men who in my judgment have rendered the best service to the progress of knowledge by their comprehensive vision, their cautious Skeptical attitude, their fearless criticism. ...