Introduction to the Purple Perils of James Gibson

This volume is a collection of James J. Gibson's (1904 - 1979) "purple perils". These "purple perils" include Gibson's notes for seminars, never intended for publication. The writings reprinted here 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 his opponents' views with greater precision and force than they had been able to achieve.

Read chronologically, these short essays also reveal important changes and revisions in Gibson's thinking, and changing patterns of influence on his work. (See Reed's James J. Gibson and the Psychology of Perception [Yale University Press, 1988] Part III for an attempt to outline these changes.)

In selecting the purple perils to be included in this collection there were several criteria. We wanted as comprehensive a collection as possible, but we did not want to reprint already published material. A few of Gibson's purple perils were published in Leonardo in the early 1970s, and we eliminated these. On the other hand, there is no way now of knowing which of Gibson's pencil manuscripts were turned into dittoed perils and which were not. There are dozens more short essays to be found in Gibson's archives than we have published here, but we have yet to find them in dittoed format. (This does not mean that they never made it to that format, just that we haven't succeeded in finding them.) Any of Gibson's writings which, as far as we know, survive only in handwritten manuscript, were eliminated from the present collection as well. What remains is a generous collection of short essays, all intended to be read and debated by students and scholars -- by anyone who cared enough about perception to attend Gibson's weekly seminar -- and all sparkling with wit and insight into the nature of human awareness.

Post Script August 5, 2001

Purple Perils in Reed & Jones

This collection on the World Wide Web represents an attempt to make available a complete collection of James Gibson's Purple Perils [unpublished 'perils' here plus those in Reed and Jones]. The 'perils' printed there, by virtue of their inclusion, became "published" works and no longer qualify for the 'unpublished' label we apply so carefully here. We did not, however, specify which essays were in Reed & Jones.

For people who would like to get closer to the complete list of 'purple perils,' we identify here all of those reprinted in Reed & Jones with a full citation.

By my count, there are 18 'perils' in Reed & Jones, 4 of which are here in the Web Collection as well. Those are identified separately below and a citation will be added to the copies here in our web collection. Because Reed & Jones is out of print, you might continue to cite this web version because it remains accessible -- bearing in mind that the Reed & Jones versions sometimes have explanatory footnotes that are not here.

Not every one of Gibson's unpublished works, printed in Reed & Jones, was a "purple peril," and there are some ambiguous cases. The list we're trying to make exhaustive is the list of "purple perils."

Please report any corrections or additions that should be made to:

Bill Mace

'Perils' in Reed & Jones and NOT in our web collection

  1. Toward a nomenclature of form, pattern and shape
    October 1967
    R&J Chapter 4.1 Part II pp. 315 - 316

  2. The affordances of the environment
    January 1972
    R&J Ch. 4.9 Part V pp. 408 - 410

  3. Note on the distinction between stimulation and stimulus information
    March 1972
    R&J Ch. 4.3 Part II pp. 348 - 349.

  4. The theory of proprioception and its relation to volition: An attempt at clarification
    June 1974
    R&J Ch. 4.6 Part I pp. 385 - 388

  5. A note on current theories of perception
    July 1974
    R&J Ch. 4.4 Part II pp. 370 - 373.

  6. Note on Perceiving in a Populated Environment
    August 1974
    R&J Ch. 4.9 Part VII pp. 411 - 412

  7. Affordances and Behavior
    April 1975
    R&J Ch. 4.9 Part VI pp. 410 - 411

  8. Note for a tentative redefinition of behavior
    June 1975
    R&J Ch. 4.6 Part II pp. 388 - 392

  9. On the New Idea of Persistence and Change and the Old Ideas that it Drives Out
    November 1975
    R&J Ch. 4.7 pp. 393 - 396

  10. A note on direct perception, various kinds of indirect apprehension, and degrees of directness
    May 1977
    R&J Ch. 3.6 Part I pp 289-292

  11. A Note on What exists at the Ecological Level of Reality
    November 1978
    R&J Ch. 4.9 Part IX pp. 416 - 418

  12. What is involved in surface perception?
    May 1979
    R&J Ch. 1.8 pp. 106-112

  13. Various kinds of cognition
    July 1979
    R&J Ch. 3.6 Part II pp. 292 - 293

  14. Ecological Physics, Magic, and Reality
    August 1979
    R&J Ch. 2.9 pp. 217-223

'Perils' in Reed & Jones that ARE in this Web collection [linked for your convenience]

  1. What is perceived? Notes for a reclassification of the visible properties of the environment
    August 1967
    R&J Ch. 4.9 Part I pp. 401 - 403

  2. A preliminary description and classification of affordances
    February 1971
    R&J Ch. 4.9 Part II pp. 403 - 406

  3. More on affordances
    March 1971
    R&J Ch. 4.9 Part III pp. 406 - 407

  4. Still more on affordances [in same file as previous memo]
    March 1971
    R&J Ch. 4.9 Part IV pp. 407 - 408