"purple perils" include Gibson's notes for seminars, never intended for
publication. The writings were meant to stimulate discussion among the
participants of Gibson's perennial perception seminar. Often this
material contained the seeds that grew into his books and articles.
By the time James Gibson had formulated his radical "ecological approach"
to visual perception, he had nearly reached retirement age. The reception
of a five year grant for a senior researcher allowed Gibson to reduce his
teaching load in the late 1960's to the above-mentioned seminar. Gibson's
seminar was held Winter, Summer, vacation or not, once a week at 4:00 PM on
Thursdays, and was a hotbed of intellectual activity and excitement. In
addition to the usual membership of Cornell graduate students and faculty,
there were frequent visitors, often from Europe, and this gave added spice
to the arguments. It was the kind of seminar that gave seminars their good
name, full of interest, enthusiasm, and excitement.
It became Gibson's practice to prepare a short, provocative essay for the
seminar. He sent these out as notes or memoranda before the seminar
meeting, in order to stimulate debate. The vast majority of purple perils
either began life as pencil notes for such essays, or as dittoed versions
of the essays. (The ditto, or hectograph, being a now-arcane form of
duplicating multiple copies of a typewritten manuscript: one types the
manuscript on a special master, and a spirit-alcohol based process
transferred the typesript from master to copy. The ditto copies typically
being purple gave rise to the term "purple peril.") In quite a few cases
the seminar discussion would cause Gibson to re-think what he had said, and
to write a followup for the next week's discussion. It is interesting to
note how few of the purple perils derive from problems in the current
literature, and how many derive from what Robbie Macleod liked to call the
"perennial problems" of psychology. Similarly, a number of the purple
perils emerged from Gibson's larger writing projects, such as his books, or
his major essays. For this reason, in Reasons for Realism: Selected Essays
of James J. Gibson (Erlbaum, 1982) the editors printed a few of the purple
perils that could be directly identified with specific published essays.
A collection of Gibson's purple perils affords considerable insight
into both Gibson's mind and his personality. These essays provided him
with an ideal format for his favorite kind of intellectual activity:
pushing ideas as far as they can go. He delighted in sharpening and
refining the hypotheses of ecological optics, and in trying to state
views with greater precision and force than they had been able to achieve.
The "Purple Perils" may be found at
With more information available at:
Search: James Gibson
A kind of clichematic thinking and the destruction of articulation
skills was also implied, amazingly enough, in:
-Lawrence Frank's "The World as a Communication Network" (c. 1962)
-Heinz von Foerster (Principles of Self-Organization,
edited by von Foerster, published by Pergamon Press, 1962).
However, one can go even earlier, from:
-Vannevar Bush's "As We May Think":
"A new symbolism, probably positional, must apparently precede the
reduction of mathematical transformations to machine processes. Then, on
beyond the strict logic of the mathematician, lies the application of logic
in everyday affairs. We may someday click off arguments on a machine with
the same assurance that we now enter sales on a cash register. But the
machine of logic will not look like a cash register, even a streamlined model."
Turing and the Universal Simulation machine: