Dualism denotes the concept that the mind and body are two distinct
substances, with the implication being that the non-physical human soul
can live on after the material body perishes. The philosopher Plato serves
as a prominent proponent of dualist beliefs as the notion of a separate
soul connects directly to his Doctrine of Two Worlds and acts as the
foundation for philosophers such as Descartes to develop dualism further.
However, dualist views on the soul do not exist unopposed, as Aristotle’s
hylomorphic understanding demonstrates a thorough criticism of dualist
belief. Thus, the strength and success of dualist ideas, as well as the
extent to which they remain relevant through a scientific lens,
necessitates examination.
Plato’s dualist beliefs are convincing as they are rooted in the concept
that the soul is the ‘real’ self and that the body is a separate substance
that is the “cause of wars and factions and battles” (‘Phaedo’) within our
self. Plato strongly argues that the soul existed before the body, in the
World of Forms, and will return there after physical death. This is
supported by the mathematician Sir Roger Penrose, who argues that
“whenever the mind perceives a mathematical idea, it makes contact with
Plato’s world of mathematical concepts”, affirming the idea of a World of
Forms that interacts with the human mind. This critically strengthens
Plato’s view through showing that Plato’s dualism has logical sense.
Furthermore, Plato claims that there are three parts of the soul: Reason,
Desire, and Spirit, and that these are in conflict until death. This
successfully gives explanation as to why humans have conflicting desires,
as seen in the illustration of the thirsty man who craves water despite
knowing it is poisoned. However, the philosopher David Hume, in ‘A
Treatise of Human Nature’, criticises Plato by stating that “Reason is, and
ought only to be the slave of the passions”, and that, as mankind is only a
“bundle of perceptions”, desires and passions are legitimate parts of man.
This severely weakens Plato’s dualist ideas as Hume is suggesting that
there is therefore no conflict between soul and body. Nevertheless, Plato
also cites the cyclical nature of opposites, highlighting that those who are
dead were once alive so the body is mortal and subject to physical death.
Thus, as he states that the soul must be the body’s imperishable opposite,
the soul must therefore be eternal and unchanging - just like the World of
Forms. There are, therefore, many reasoned and comprehensible
arguments to support Plato’s ideas.
However, Aristotle’s contrasting beliefs pertain to empiricism and thus
centre upon human experience, arguing that the soul and body are not
separate. Naturally, therefore, Aristotle’s ideas can be logically
understood by humans, whereas dualism is far less comprehensible. In
‘De Anima’, Aristotle explains his view of the soul using three illustrations,
one of which is stamping a wax tablet, as the impression made cannot be
separated from the stamp, just as the soul cannot be separated from the
body. An axe is also illustrated to demonstrate how the soul is closely