34
JANE Μ. OPPENHEIMER
the century, invoked the qualities of the ground substance of the cytoplasm to account for what he could not explain on the basis of visible
inclusions, he was retreating not away from but towards the metaphysical.
When contemporary embryology turns to the ground substance in its
now known ultramicroscopic structure to elucidate, say, the development of the nervous system (Weiss, 1955), it believes it passes from the
metaphysical towards the physical. Making the invisible visible and the
minute mathematically comprehensible is not necessarily synonymous,
however, with leading away from the metaphysical towards the physical.
The difficulty is to calculate the measure in which descriptions and explanations couched in terms of the ultramicroscopic, when this is molecular, are themselves physical or mathematical. This becomes a function
of what physical science itself makes of the molecule and the atom; and
some possibility surely exists in the middle of the 20th century that these
entities may be now less physically and more metaphysically conceived
than they were at the end of the 19th.
If so—and indeed in any case—the highly pertinent question arises as
to the extent to which 20th century embryology stands in peril of remaining under domination by 19th century rather than 20th century
physical concepts. To return again for a moment to Roux, one importance
of his contribution lay in his recognition of time as a prime factor whose
effects were open to experimental investigation. As a creature of the
19th century he related his primary question concerning it to a 19th century conception of causality which 20th century physical science considers outdated. Yet all of our embryological principles, such as they
are, developed as they have been in the wake of Roux's passage, suffer
the same defect. We have said earlier that the methods of 20th century
embryology began by being essentially those of the 19th. So also began,
and still continue to be, its philosophical foundations.
Occasionally, in the text of this essay, a musical metaphor has been
followed. This was something more than a frivolous literary conceit; it
has been designed to draw attention to the fact that there may be more
ways than one of looking at a sequence of events in time. It happens that
very occasionally either a romantic biologist (see von Uexküll in his enchanting piece "Der unsterbliche Geist in der Natur/' 1946) or a romantic aesthetician (Carriere, 1859) has drawn an analogy between a
developing organism and a musical composition, but this has been on
the whole an exceptional rather than a usual occurrence.
15
Now this is
15
One is tempted to wonder what might have been the outcome for embryology—
and indeed for teleology more generally—had the music of Aristotle's day been such
that he could have compared the development of an embryo to composing a musical
opus rather than painting a picture.
JANE Μ. OPPENHEIMER
the century, invoked the qualities of the ground substance of the cytoplasm to account for what he could not explain on the basis of visible
inclusions, he was retreating not away from but towards the metaphysical.
When contemporary embryology turns to the ground substance in its
now known ultramicroscopic structure to elucidate, say, the development of the nervous system (Weiss, 1955), it believes it passes from the
metaphysical towards the physical. Making the invisible visible and the
minute mathematically comprehensible is not necessarily synonymous,
however, with leading away from the metaphysical towards the physical.
The difficulty is to calculate the measure in which descriptions and explanations couched in terms of the ultramicroscopic, when this is molecular, are themselves physical or mathematical. This becomes a function
of what physical science itself makes of the molecule and the atom; and
some possibility surely exists in the middle of the 20th century that these
entities may be now less physically and more metaphysically conceived
than they were at the end of the 19th.
If so—and indeed in any case—the highly pertinent question arises as
to the extent to which 20th century embryology stands in peril of remaining under domination by 19th century rather than 20th century
physical concepts. To return again for a moment to Roux, one importance
of his contribution lay in his recognition of time as a prime factor whose
effects were open to experimental investigation. As a creature of the
19th century he related his primary question concerning it to a 19th century conception of causality which 20th century physical science considers outdated. Yet all of our embryological principles, such as they
are, developed as they have been in the wake of Roux's passage, suffer
the same defect. We have said earlier that the methods of 20th century
embryology began by being essentially those of the 19th. So also began,
and still continue to be, its philosophical foundations.
Occasionally, in the text of this essay, a musical metaphor has been
followed. This was something more than a frivolous literary conceit; it
has been designed to draw attention to the fact that there may be more
ways than one of looking at a sequence of events in time. It happens that
very occasionally either a romantic biologist (see von Uexküll in his enchanting piece "Der unsterbliche Geist in der Natur/' 1946) or a romantic aesthetician (Carriere, 1859) has drawn an analogy between a
developing organism and a musical composition, but this has been on
the whole an exceptional rather than a usual occurrence.
15
Now this is
15
One is tempted to wonder what might have been the outcome for embryology—
and indeed for teleology more generally—had the music of Aristotle's day been such
that he could have compared the development of an embryo to composing a musical
opus rather than painting a picture.