Have Worlds Inside Us’.^27 Looking back, humans are relative newcomers in the
history of the planet; looking forward, we presumably must share the fate of every
species over the longest run by becoming extinct or being replaced.^28 How the
human collective conceives international politics, as one of the expressions of how
we live globally, will have a part in how that story eventually plays out.
Pictures diagrammatically expressed
Darwin theorised in pictures. It is difficult to think, anywhere, of a more powerful
theory-as-picture to compare with Darwin’s tree-of-life image, with the words ‘I
think’ written just above it. Desmond and Moore commented as follows on the
drawing:
Given his heritage of anti-slavery and human brotherhood, and his shock at
seeing slavery in the raw during the Beaglevoyage, it is no surprise that
Darwin, on arriving home, used the human genealogical image to model the
‘common descent’ of all life.^29The tree-of-life diagram was already ‘firmly lodged in his mind’ by the time of his
first evolution notebook (July 1837). This diagram has proved to be a remarkable
theory-as-picture, representing a family tree of the actual if not actualised brother-
hood of all living things.
Waltz too thinks in pictures, though he has not written books with diagrams.
Man, the State and War was famously organised around three ‘images’. These became
(usually renamed ‘levels of analysis’) a notably influential picture of reality for
subsequent International Relations theory. This leads to my final set of arguments.
Levelling with the international
The level-of-analysis image in International Politics is the idea that we can conceive
different sites of explanation, where we ask good questions and find plausible
answers. The upper level is the ‘system’, and below it are various ‘unit’ levels
(such as states or individuals). A key response to Waltz’s original ‘images’ in Man,
the State and War was J. David Singer’s seminal 1960 review of the book, followed
by an influential article a year later.^30 The level-of-analysis framework became part
of the language of international politics. For some it became difficult to think of the
field apart from some notion of ‘levels’, though for others it has remained
contentious.^31
The disagreements about level-of-analysis thinking have taken various forms:
over what is a ‘level’; over the number of relevant levels in international politics;
over the most influential level for explaining particular phenomena; and over the
separateness of the levels and how they fit together. Some reject thinking in these
terms at all, though other branches of the Social Sciences – Sociology and
Economics – have found such frameworks helpful. Used carefully, the framework
334 The inconvenient truth