Principios de Taxonomia

3.4 The Difference Between a Group of Objects as a Class and a Group of Objectsj51
Ultimately, the biological species cannot be a class. Of course, trait-equivalent
organisms can be grouped into a class, but (if applied to biological organisms) this
procedure would contradict the laws of evolution. Each attempt to unite organisms
into classes leads to artificial constructs that are fictive units that do not exist in reality.
3.4
The Difference Between a Group of Objects as a Class and a Group of Objects as an
Individual is a Fundamental One
A group of objects is always either a class or an individual (Ghiselin, 1997; De Sousa,
2005). A group can never be both a class and an individual at the same time, nor can
class and individual be mixed. These differences can be summarized as follows:
1) The individual exists in space and time: An individual always occupies a region of
space and exists at a certain time. Because an individual exists at a certain time, it
always has a beginning and an end. At a certain time in the past it did not exist, and
at some point in the future it will no longer exist. An individual is a historically
fleeting occurrence. When the individual has become extinct or has been
exterminated, it cannot reoriginate. The Eiffel Tower has a founding date, and
one day it will no longer be there. A newly constructed, similar-looking tower at the
same or different location is no longer the Eiffel Tower. The Polar Bear (Ursus
maritimus) originated approximately 200 000 years ago (Breiter, 2008), and due to
the current climatic change, pessimists predict its early demise.
In contrast, a class is not restricted to a region of space or a particular time of
existence. A class cannot begin to exist and it cannot become extinct. Because a
class is a group of several organisms based on common properties, a class can exist
everywhere, every time, provided that the objects of the classification are present.
As long as the objects are there, it is inconceivable that a class would exist at only
one point in time. If a class exists at a particular location, then it can also
simultaneously exist at a different location in the universe. Likewise, a class
might exist once at a particular time but then again later at a second or third time.
The multiple occurrence in space and time must not be realized in our world, but
no contradiction arises if this concept is assumed. The only requirement is that the
objects with similar traits are again present at other locations or at other times.
In every imaginable world there will be a class of red objects, provided that red
objects exist there, and in the distant future there will always be a class of red
objects. Any claim that the class of red objects had become extinct would be
meaningless.
Let us apply this concept to the Polar Bear. Of course it is possible to construct a
class into which the existing Polar Bears fit well. This class would be a group that
combines a number of properties such as white fur, other morphological traits,
and species-specific behavior. However, this is an artificial group. Whenever there
are animals on another planet or at a different geological time that could fit into
this class, one can apply the class concept to these organisms without any