That our conceptions of reality shape the nature of our experience has been so well documented as to need little explanation. In the sciences, we could not have reached the moon without the formulations of Copernicus - who saw the sun, not the earth, as the center around which the planets revolve. In the realm of social theory, we could not have dispelled the institution of slavery without an elevated conception of the sanctity of human life.
In education, too, the development of a new definition or metaphor - a new model for looking at students, teachers, and learning - should have similarly far-reaching effects. That, at least, is the hope of the Paideia Group, a body of highly respected American educators who have recently been rethinking the philosophy of primary and secondary education. Last week saw the publication of their third and final book (''The Paideia Program: An Educational Syllabus'').
As Mortimer J. Adler, the group's chairman, explains in his introduction, the program stands squarely against elitism - against the so-called ''two track'' system which divides students into those destined for the work force and those destined for college. The rest of the book - comprising essays by such notables as Adler, Theodore Sizer, Jacques Barzun, and Charles Van Doren - stands just as squarely in favor of real excellence in the content and methodology of teaching.
That said, this is still a book based on two old metaphors: that of ''tracks, '' and that of ''containers.'' Granted, Adler & Co. have resolved the old two-track approach into a single-track model. That's a progressive step. It produces, as he rightly says, ''equality of opportunity'' among students - although it admits to ''inequality of results.'' For although under the new system students should be ''given the same quality of schooling along a single track,'' he writes, ''all cannot be expected to move the same distance along that track.'' Why not? Because of what he calls ''the differential capacities of the children.'' He likens the students to ''containers of different sizes'': Educational success occurs, he says, when each child is ''filled to the brim, the half-pint container as well as the gallon container.''
Now, that is clearly a metaphorical description. Young minds are much more than empty pots to put things in. They are vital, expansive, alive - more accurately depicted, perhaps, as a glow radiating outward than as a shell surrounding a void. In fairness, Adler uses his metaphor to make an excellent point: that what gets taught should be of uniform quality, and that we should stop giving cream to some and skim milk to others. But it is metaphor nonetheless, and it has a disturbing effect on the entire argument.
For one thing, it allows teachers to continue subjecting students to self-fulfilling prophecies. True, they may no longer tell themselves that ''Bookmaster here is headed for college, but Boltwell's only going to work in a garage.'' They are still permitted, however, to recognize that while Boltwell can hold but half a cup, Bookmaster is clearly worth two quarts - and to shape their expectations of each one accordingly.
But the greater danger has to do with Adler's other metaphor: that of tracks. His conception, implying a kind of linearity to human experience, is akin to popular cliches suggesting that we are all ''climbing the ladder of success'' or ''only going around once.'' Success, in these terms, is intensely competitive. It implies getting ahead of others along a track that leaves no room for movement except in two directions - and no room for more than one person to be in one place at one time.
At this advanced stage of the post-Copernican age, can we not do better in our metaphors? What would be the result of an educational system built, for instance, on the image of spheres instead of lines? What if each student, rather than being seen as a point on a track, were defined by a set of coordinates on a globe - a kind of mental longitude and latitude? Points on a line, like pots of different sizes, almost always carry with them value judgments: Put a ''plus'' and a ''minus'' at the ends of the line, and you have instantly ranked every student. But points on a sphere have no ranking relative to one another: No one would argue that Iceland is superior to the Azores simply because it is ''higher'' on the globe. Each exists at its own particular longitude and latitude - at a location unique to itself.
Is this mere poetics? No, for it raises what I take to be the central educational question of the day: How do we deal with uniqueness? Of course it is easier to treat students as though they were points on a line. Of course it is easier to rank them. But what if students aren't like that? What if they all come with their own individual sets of coordinates - each different, and each basically incomparable to the others? If that's true - and my own experience as a classroom teacher leads me to think it is - then our conception of education may have to move as far as Copernicus moved from Ptolemy before it accurately assesses the nature of reality. Otherwise, we'll simply continue to mix our metaphors - trying to fit (as it were) the spherical pegs of our students into the linear holes of a system made of tracks and pots.