Howie asked:

Could you compare the rational, scientific and existentialist theories of human nature? What do you
think is the most important feature of humanity?

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The theory of a human being as a rational subject belongs to analytical philosophy. Plato and
Aristotle described man as rational and both thought that it is through the use of reason that we
become better human beings. Descartes identified the subject as essentially a thinking subject. From
these starting points, analytical philosophers have engaged in discussion of issues such as the nature
of rationality, means/end reasoning, and how the subject relates to or adopts normative principles.

Existential theories, in stark contrast, look at the non-rational side of man's inner nature, such his
freedom, his dread, anxiety and fear of death, guilt and responsibility. Consideration is given to what it
is to be, or exist, as mankind in relation to his environment that is quite different to Cartesian
approach that considers the nature of man as a lone subject.

You cannot easily choose whether or not it is more important that man is rational or an emotional
agent in the world because man is essentially both. If you took man's rational nature away, it is hard
to how that he could experience guilt, responsibility or decide to act in virtue of his freedom. Thought
is essentially involved. If you took away man's non-rational view of himself as perfectly free, subject to
dread, anxiety and guilt, you would have a strange being compelled by rational principles.

A scientific theory would presumably be biological and neurological. Scientific theories see man as an
object and are important for medical reasons, and while it is an important feature of humanity that we
are able to increase knowledge our physical nature, it leads to the possibility of genetic engineering,
which is morally dubious.

Rachel Browne