(3) The distinction between public and private is by no means the same as that between physical and mental. That is .why methodological behaviorism (which adopts the first) is very different from radical behaviorism (which lops off the latter term in the second). The result is that while the radical behaviorist may in some cases consider private events (inferentially, perhaps, but none the less meaningfully), the Boring-Stevens operationist has maneuvered himself into a position where he cannot. 'Science does not consider private data,' says Boring. (Just where this leaves my contribution to the present symposium, I do not like to reflect.) But I contend that my toothache is just as physical as my typewriter, though not public, and I see no reason why an objective and operational science cannot consider the processes through which a vocabulary descriptive of a toothache is acquired and maintained. It is an amusing bit of irony that, while Boring must confine himself to an account of my external behavior, I am still reasonably interested in what might be called Boring-from-within.