The philosophical meaning of life concerns such questions as the significance of life. Plato argued that the meaning of life lay in the optimal attainment of knowledge. Just like previous predecessors, Plato believed that this knowledge was in the form of the good. Just and good things derive their utility and value from the good in them. This good exists in terms of justice. Plato referred to justice as the social virtues that exist in any society. To locate these social virtues, he proposes the use of an ‘elimination method’ (Plato, 428B- 445E).