briar-patch

Noun

 * 1)  A dense thicket of thorny plants; ground made impassable by the impenetrable overgrowth of prickly vegetation.
 * 2)  An intellectual or philosophical issue abounding with seemingly unresolvable problems; a theoretical quandary or impasse.
 * 3) * 1954: Gilbert Ryle, Dilemmas: The Tarner Lectures, 1953, dilemma vii: Perception, page 94 (The Syndics of the Cambridge University Press)
 * I do not want to spend long in examining the arguments for this general deprecation of sense-perception or the intellectual motives for denying all credentials to sense-perception in order to enhance those of calculation, demonstration or religious faith. I want to get quickly to the much thornier briar-patch, the place, namely, where scientific accounts of perception seem to issue in the consequential doctrine that observers, including the physiologists and psychologists themselves, never perceive what they naïvely suppose themselves to perceive.
 * I do not want to spend long in examining the arguments for this general deprecation of sense-perception or the intellectual motives for denying all credentials to sense-perception in order to enhance those of calculation, demonstration or religious faith. I want to get quickly to the much thornier briar-patch, the place, namely, where scientific accounts of perception seem to issue in the consequential doctrine that observers, including the physiologists and psychologists themselves, never perceive what they naïvely suppose themselves to perceive.