Hossein Jorjani
First publication: 2026 – 07 – 20
Scientific inquiry frequently employs idealizations. Their legitimacy depends upon whether the features omitted are irrelevant to the problem under investigation. In classical mechanics, for example, a planet may often be represented as a point mass without significantly affecting the accuracy of gravitational calculations. Such simplifications are justified because the planet’s internal structure is largely irrelevant to the phenomenon being explained.
Philosophy likewise employs idealizations. Moral and political theories often speak of “the individual,” “the rational agent,” or “humanity” as though these referred to a single representative human being. Such abstractions may be useful, but their legitimacy depends upon the state of empirical knowledge concerning human nature.
In Kant’s time, the available scientific understanding of humanity was limited. Newtonian mechanics represented the highest achievement of natural science, whereas biology had not yet developed a comparable theoretical foundation. Under those historical circumstances, treating humanity as a relatively homogeneous category was methodologically understandable.
The scientific situation has changed profoundly. Darwin’s theory of evolution, the Modern Synthesis, evolutionary biology, behavioral ecology, genetics, genomics, and related disciplines have revealed that human populations and individuals exhibit substantial biological and behavioral variation. They have also shown that cooperation, competition, reciprocity, altruism, and other social behaviors may arise through multiple evolutionary pathways rather than from a single universal disposition.
These developments do not determine moral or political philosophy, nor do they prescribe ethical principles. They do, however, change the empirical background against which philosophical theories are constructed. Philosophical accounts of human behavior can no longer assume, without justification, that humanity may be represented by a single abstract individual whose characteristics adequately stand for all.
The history of philosophy therefore illustrates an important methodological lesson. Idealizations remain indispensable, but they must evolve together with scientific knowledge. An abstraction that was justified under one state of knowledge may require revision when subsequent scientific discoveries reveal dimensions of reality that had previously remained unknown.
Hossein Jorjani 