 Berlin himself insisted that political and ethical theories arise from a thinker’s basic conception of human nature, which in turn is founded on an entire philosophical outlook, a conception of the nature of the universe, reality, knowledge etc. The vision underlying Berlin’s political and ethical theory, while it may have been coherent (this is itself arguable), was not systematic, and, again, it cannot be accurately characterised simply as pluralistic or liberal. ‘Pluralism’ can be used, more narrowly, to describe Berlin’s theory of values. It can also be employed more broadly, to capture something of his vision of reality, the universe and human nature – that is, the view that all of these things are complexes made up of separate and conflicting parts: that the self is protean and open-ended, that the universe is not a harmonious cosmos, that reality presents many separate aspects, which can and should be viewed from different perspectives. But ‘pluralism’, as explicitly defined by Berlin and others, does not cover Berlin’s empiricism, or his historicism, or his awareness of the fallibility of human knowledge, or his belief in the primary importance of individuals as opposed to generalisations and abstractions, or his emphasis on the importance of free choice (which, while he sought to found it on pluralism, in fact appears to be partly independent of it). Nor does pluralism, with its emphasis on the place of tragic conflict and loss in human life, capture the affirmative zest for life and delighted enthusiasm for human beings that was central to Berlin’s persona as a man and thinker. Berlin’s thought, like his writing, is made up both of swathes of sharp colour and of minutely variegated and subtle shades of light and darkness; it thus resists summary and simple conclusions, and repays persistent and open-ended study.