Identità elementare e identità genetica. La nozione di “genidentità” in Kurt Lewin

The notion of genidentity, developed

by Kurt Lewin in his initial “epistemological”

phase, is alternative both to the substantial identity,

which is based on the principle of “simple identity”

and is not able to give an account of the changes of

the same (physical or biological) being over time,

and the simple diachronic identity, forced to resort 

to external properties to ontological determinations

of an object, such as the unity of consciousness, or

the permanence of linguistic designation. Against

these “extensional” qualifications, Lewin proposes

an intensional notion of identity whose explanatory

power is close in many ways to the prospect of genetic-

constitutional “objectual whole” carried out

in the first two decades of the twentieth century by

Husserl’s phenomenology and Stanisław

Leśniewski’s mereology. The identity has for

Lewin a relational form, which turns into the different

ways of objectual identifying. Time and causality

impose themselves therefore as identification

criteria among different “genetic series”, which are

connected according to an empirical-analogical

principle of comparison. So, the ontology expresses

the structure of the topological relations among objects,

i. e. the set of relationships among the various,

unitary and continuous, “world-lines”, within

which the physical and biological bodies takes their

place.