With the advent of the relativity theory science has entered a transformative period in which previous certainties are undergoing critical scrutiny and renovation. Critical movements in science arise at periods of its history when its foundations are brought into question. True it is that natural philosophers still regard science as a growing body of propositions dealing with natural events enabling them to find the structural laws of the external world. But this “external world” about them changes in significance, interpretation, and meaning as new epoch-making theories are propounded and experimental verification of some of their consequences tend to give them scientific plausibility.

“He's [the Red King's] dreaming now,” said Tweedledee: “and what do you think he's dreaming about?”

Alice said, “Nobody can guess that.”

“Why, about you!” Tweedledee exclaimed, clapping his hands triumphantly. “And if he left off dreaming about you, where do you suppose you'd be?”

“Where I am now, of course,” said Alice.

“Not you!” Tweedledee retorted contemptuously. “You'd be nowhere. Why, you're only a sort of thing in his dream!”

“If that there King was to wake,” added Tweedledum, “you'd go out—bang!—just like a candle.”

“I shouldn't!” Alice exclaimed indignantly. “Besides, if I'm only a sort of thing in his dream, what are you, I should like to know?”

“Ditto,” said Tweedledum.

“Ditto, ditto!” cried Tweedledee.

He shouted this so loud that Alice couldn't help saying “Hush! You'll be waking him, I'm afraid, if you make so much noise.”

“Well, it's no use your talking about waking him,” said Tweedledum, “when you're only one of the things in his dream. You know very well you're not real.”

“I am real!” said Alice, and began to cry.

“You won't make yourself a bit realler by crying,” Tweedledee remarked: “there's nothing to cry about.”

“If I wasn't real,” Alice said—half laughing through her tears, it all seemed so ridiculous —“I shouldn't be able to cry.”

“I hope you don't suppose those are real tears?” Tweedledum interrupted in a tone of great contempt.

—Through the Looking Glass

The boundaries of psychology have never been very distinctly defined and, as a consequence, science has witnessed frequent border incidents. But it obviously is not psychology alone which suffers from such lack of delineation, but its neighbors, the biological and social sciences, do as well. Cooperation between sciences becomes difficult under these conditions. All agree that psychology is the science of mind, but few agree to what “mind” is. At least within our century “mind” has been taken to be “behavior”, for the present day outlook is that mind is behavior rather than that which is responsible for behavior (3). The metaphysical dynamism of a prime mover has been replaced by an experimental concept, i.e., one that is susceptible to scientific investigation. There is no need to review the complex history of behavioristic psychology in its many ramifications, ranging from Watson's mechanism to the various vitalistic teleologies. We turn instead to a fundamental problem on which there is little agreement: “What kind of behavior should be called mind?”

The major question—what is categorial analysis and how can it be reliably performed?—lies beyond the scope of this paper. Indeed, I would presume that very little can be said significantly about it in general. One's convictions on the subject have to be shown by actual performance, which is my intention in the present instance. But it may help the process of communication if I try to indicate at the beginning the general frame in which this analysis of value occurs.