The chapter wonders why James Harrington’s vocabulary, especially that of ‘balance’ and of ‘interest’, pervades Shaftesbury’s psychological discourse in Characteristicks, far beyond what has so far been acknowledged by commentators. The purpose of the chapter is to establish that Shaftesbury’s discreet use of Harrington in his Characteristicks was not simply a conniving glance at fellow Old Whigs, unhappy with the conversion of Country to Tory, but that it included broader concerns in terms of a philosophical as well as political agenda. Shaftesbury was sensitive to the way in which Harrington revived the ancient analogy between political constitution and the human soul, constitutional balance and psychological temper, thus reconnecting the question of political justice with that of justice in the individual. The first section clarifies the various senses of the term ‘balance’ in this context. The next section deals with Shaftesbury’s understanding of ‘constitution’ as relevant in the field of psychology as well as of political philosophy. The true “notion of a public and a constitution” requires ways to maintain psychological or political unity without sacrificing deliberative pluralism. In the last section, The last section tackles the problem of how a human soul as well as a political body may become less partial, more universal, according to the third Earl. The main problem, of a practical nature, is about how to be more rational, individually or collectively. Is ‘natural affection’, as a built-in bent towards the good of others sufficient to lead frail agents to ‘love’ and promote the public good? Or does it also require method and art? Shaftesbury’s insight into this practical problem borrows from Harrington’s “philosophy of the soul”. What the author of Oceana taught Shaftesbury is that impartiality in the sense of the promotion of public good does not simply rest upon good-natured dispositions, but is constructed or at least directed.