Customer Service | Help | FAQ | PEP-Easy | Report a Data Error | About
Tip: To use Evernote for note taking…

PEP-Web Tip of the Day

Evernote is a general note taking application that integrates with your browser. You can use it to save entire articles, bookmark articles, take notes, and more. It comes in both a free version which has limited synchronization capabilities, and also a subscription version, which raises that limit. You can download Evernote for your computer here. It can be used online, and there’s an app for it as well.

Some of the things you can do with Evernote:

  • Save search-result lists
  • Save complete articles
  • Save bookmarks to articles


For the complete list of tips, see PEP-Web Tips on the PEP-Web support page.

Jekels, L. (1945). A Bioanalytical Contribution to the Problem of Sleep and Wakefulness. Psychoanal Q., 14:169-189.

(1945). Psychoanalytic Quarterly, 14:169-189

A Bioanalytical Contribution to the Problem of Sleep and Wakefulness

Ludwig Jekels, M.D.

Johannes Müller, the great physiologist and teacher of Helmholtz, Dubois-Reymond and Ernst Brücke—to mention only the greatest names among the pleiad of his disciples—is said to have coined the aphorism: Physiologus nemo nisi psychologus.

There is probably no better proof of this saying in the history of physiological research than the striving of physiologists to understand the problem of sleep. In order to illustrate their almost complete failure with this problem—which has for many centuries been a subject of persistent research—I quote the statement of a witness who is the more dependable since he is not compromised by psychology. The physiologist Kleitman of Chicago has studied the problem of sleep for twenty-two years—mostly experimentally—has contributed numerous papers to it, and has recently published a book of more than five hundred pages entitled Sleep and Wakefulness. In this work he enumerates no fewer than one thousand four hundred and thirty-four references, all of them published since 1912. His last chapter begins with the words: 'It is commonly stated that we know nothing or practically nothing as to what causes sleep'.

Johannes Müller's aphorism was fully verified by Freud at the turn of the century and in subsequent decades when he emphasized the participation of psychological factors in sleep, thus characterizing it as a psychobiological phenomenon. This was a revolutionary step. Not only did it lead to the abolition of the prevailing concept of sleep, but it opened up a path for further research.

[This is a summary or excerpt from the full text of the book or article. The full text of the document is available to subscribers.]

Copyright © 2019, Psychoanalytic Electronic Publishing, ISSN 2472-6982 Customer Service | Help | FAQ | Download PEP Bibliography | Report a Data Error | About

WARNING! This text is printed for personal use. It is copyright to the journal in which it originally appeared. It is illegal to redistribute it in any form.