As we discussed yesterday: a child will begin working with a concept of dog with only one data point: Fido. Nobody waits, or should wait, for enough material to build up a table of similarities and contrasts. The building of assumptions and experimentation begins immediately. Meeting the neighbors' dog is simply an early experiment in one's life. The neighbors' dog may be much larger than our own family dog: I may have to revise my view that dogs fit naturally on human laps, like Fido. Ah, but what does that have to do with us? One might ask. "There are only adults in this room." Still: there are matters on which we have only one datum. Consider life on Earth. We know as of yet of only one planet that hosts life. We have hypotheses about others, and a huge body of fiction on the subject. But we have no reliable information about any other such planet. This is NOT an example of Dewey's. [He was writing How we think only a few years after ...