12
JANE Μ. OPPENHEIMER
take into account—or at least have not sufficiently emphasized in their
technical publications—is that attempted reference of the qualitative to
the quantitative is not a concern unique to morphogenetic study alone.
The whole history not only of biological but also of physical science has
exhibited a steadily mounting practice of attempting to derive the supposedly qualitative from the supposedly quantitative. Yet in the last
analysis, the relation of quality to quantity remains now, as it has been
during the whole development of human thought, one of the thorniest
problems to vex the complacency of philosophy, and even today some of
the keener of the modern philosophers of science consider the whole
dualism postulated between the qualitative and the quantitative to rest
only very insecurely on fallacious logical grounds (see for instance the
illuminating essay, Malicious Philosophies of Science, by Nagel, 1954).
Perhaps, however, the ultimate demonstration of the complementariness of the axial gradient and the organizer concepts is that at least one
subsequent concept is of such a nature as to be able to encompass them
both, namely, the field concept. Priority for this, so far as ideas rather
than name is concerned, is due to Harrison (1918), though Spemann
(1921) considered the organizer to produce what he called a field of
organization. It is rather a singular fact, however, that this concept has
never acquired quite the general popularity and prestige of the other
two under discussion, perhaps partly because its validity is so completely
taken for granted by working embryologists, perhaps partly because
no writing embryologist has yet taken the trouble to construct a single
monolithic volume in which all known embryological data are subjugated
to generalization in terms of fields. The closest approach to such a treatment is that of Huxley and DeBeer (1934), who have accounted for a
number of morphogenetic data on the basis of what they call gradientfields; these however are probably more closely identical to Child's axial
gradients than now, more than twenty years later, seems appropriate or
desirable.
While the field theory has not yet been adequately developed, Weiss
(1926) deserves considerable credit for having generalized it on a
theoretical basis to cover morphogenetic phenomena. Analogy with a
strictly physical concept is explicit in it—at a much more sophisticated
level than in Driesch's metaphor referred to above. While at the moment
its value is descriptive rather than analytical, it may yet become useful in
fostering comprehension of the newer embryological data, within the
limitations, of course, that circumscribe the applicability of 19th century
physical theory to 20th century embryological interpretation.
The field concept as such has, however, so far led less directly in the
JANE Μ. OPPENHEIMER
take into account—or at least have not sufficiently emphasized in their
technical publications—is that attempted reference of the qualitative to
the quantitative is not a concern unique to morphogenetic study alone.
The whole history not only of biological but also of physical science has
exhibited a steadily mounting practice of attempting to derive the supposedly qualitative from the supposedly quantitative. Yet in the last
analysis, the relation of quality to quantity remains now, as it has been
during the whole development of human thought, one of the thorniest
problems to vex the complacency of philosophy, and even today some of
the keener of the modern philosophers of science consider the whole
dualism postulated between the qualitative and the quantitative to rest
only very insecurely on fallacious logical grounds (see for instance the
illuminating essay, Malicious Philosophies of Science, by Nagel, 1954).
Perhaps, however, the ultimate demonstration of the complementariness of the axial gradient and the organizer concepts is that at least one
subsequent concept is of such a nature as to be able to encompass them
both, namely, the field concept. Priority for this, so far as ideas rather
than name is concerned, is due to Harrison (1918), though Spemann
(1921) considered the organizer to produce what he called a field of
organization. It is rather a singular fact, however, that this concept has
never acquired quite the general popularity and prestige of the other
two under discussion, perhaps partly because its validity is so completely
taken for granted by working embryologists, perhaps partly because
no writing embryologist has yet taken the trouble to construct a single
monolithic volume in which all known embryological data are subjugated
to generalization in terms of fields. The closest approach to such a treatment is that of Huxley and DeBeer (1934), who have accounted for a
number of morphogenetic data on the basis of what they call gradientfields; these however are probably more closely identical to Child's axial
gradients than now, more than twenty years later, seems appropriate or
desirable.
While the field theory has not yet been adequately developed, Weiss
(1926) deserves considerable credit for having generalized it on a
theoretical basis to cover morphogenetic phenomena. Analogy with a
strictly physical concept is explicit in it—at a much more sophisticated
level than in Driesch's metaphor referred to above. While at the moment
its value is descriptive rather than analytical, it may yet become useful in
fostering comprehension of the newer embryological data, within the
limitations, of course, that circumscribe the applicability of 19th century
physical theory to 20th century embryological interpretation.
The field concept as such has, however, so far led less directly in the