Plato's Mind Body Problem

Previous Content Next


In the Republic Plato does not attempt to give a philosophical or ‘scientific’ account of the soul (or mind). It is accepted without question. Plato treatment of the soul has relevance for both his ethics and his political philosophy. Firstly, Plato discusses the nature of the soul, putting forward a ‘tripartite’ model. Secondly, he is interested in its immortality.

Plato’s Tripartite Soul

Plato’s tripartite model of the soul is derived from his observations of the city-state. In Plato’s imaginary state unity is preserved by people knowing and keeping to their class. The workers are the body and limbs of the state, the auxiliaries its heart, philosophers its head. Plato argues these divisions within the city-state these must have arisen from the individuals which make up society. Plato’s views on morality depend crucially on his psychology: morality and other kinds of virtue are special states of mind, in which the parts of the mind are disposed and related in certain ways. Plato’s psychology is central to his Republic.

Plato claims to have detected three main sources for motivation within people:

  • Desire to satisfy one’s instincts
  • Desire for preservation
  • Desire for understanding and truth

Each part of the mind not only has the ability to desire but also some cognitive ability. For example in the desire to quench one’s thirst there is the cognitive ability to recognise a drink. Plato talks about the ‘non-rational’ parts of the mind having beliefs or views. It is the job of reason to perceive goodness. It is the unsullied rational part which perceives and knows what is good for a person. Other parts recognise goods which are more restricted i.e. goods which are short term or non-altruistic. Such parts are limited to calculating how to achieve them.

Plato believed that one could be ‘ruled’ by a part of a mind. To perceive goodness is to act on it.

In short the three divisions are:

  • Irrational (to epihumetikon – το επιθυμητικον) – that in which one’s cardinal appetites reside
  • Reflective (to logistikon – το λογιστικον) – using one’s reason, being skilled, calculating or mathematical
  • Spirit (to thumoiedes – το θυμοειδες) – that in which one’s courage and higher passions reside

Plato derives these three divisions in two stages.

Firstly, starting with desire, he notes that it may be either unqualified or qualified. For example, someone may thirst without qualification – not caring about what or how much they want to drink. In this case drink is the ‘natural object’ of thirst. But thirst may also be qualified. Someone may desire a lot or a little to drink. Likewise, someone may desire a particular kind of drink and so can be said to have a particular kind of thirst. Plato concludes that there is an ‘irrational’ element to the soul which desires the drink, and a ‘reflective’ element which categorizes it as little or much, sweet or bitter, and so on.

Secondly, Plato notes that children are able to exercise a degree of self control long before they have the rational. He calls this element ‘spirit’ or ‘indignation’. This third element comes to the help of the reason when it is struggling against desire. Plato compares the rational element to a charioteer trying to control two horses, one good (the spirited element), the other bad (the appetitive element). The first horse is obedient to the charioteer’s instructions while the other has to be restrained by the whip. Indignation is distinct from appetite while at the same time having an affinity with reason. Plato warns that indignation may become corrupted by bad upbringing.

Previous Content Next