agathon Greek word meaning ‘a good’ or ‘the good’. From Socrates onward, agathon was taken to be a central object of philosophical inquiry; it has frequently been assumed to be the goal of all rational action. Plato in the simile of the sun in the Republic identified it with the Form of the Good, the source of reality, truth, and intelligibility. Aristotle saw it as eudaimonia, intellectual or practical virtue, a view that found its way, via Stoicism and Neoplatonism, into Christianity. Modern theories of utility can be seen as concerned with essentially the same Socratic question. R.C.