Sloterdijk's three volumes of Spheres are not as yet translated into English. Blog entries with titles containing Sloterdijk's name discuss ideas and language of the first volume.

In Third Excursus, Sloterdijk sketches the revolution introduced by William Harvey's groundbreaking scientific hypothesis on egg as a single omnipresent precondition of procreation. Although Harvey didn't have the means that would have allowed him to corroborate his ideas with some exact observations, his generalization of 'the egg principle' is unexpectedly daring, filled with unrestrained enthusiasm and altogether goes one step further than the old, mythological (and philosophical) notions of egg as the cradle of universe.

This historical digression is intertwined with very instructive remarks on (mythological/metaphysical) thinking that is oriented towards 'source' (of all things), which is represented, at times, as egg. That kind of thinking, with its internal rules and logic, is something that Sloterdijk leaves behind in his pursuit of new, medial modalities of reality and its interpretation. It is Hegelian dialectics, combined with Heideggerian puns and wit, that characterizes following short commentaries on 'egg principle': with its magic symmetry egg has since early days of mankind symbolized 'cosmosization' of the chaotic universe; egg is also symbol that teaches us to think simultaneously the protective form and its destruction since egg is a shelter from the world, but one that has to be broken and removed; it is the source, but we cannot think of source and not think about distancing and freeing ourselves from it, and freedom from the source is the freedom that keeps within itself the relation to source; and so, broken egg shell is not the last word, it prompts us to ask whether that coming-out-from-inside into the world is really coming into the open or rather entering some other, bigger egg that contains us, together with our relation to source of our being; thing that was lost once the shell was rejected, now is being restored allover, on the higher level; old Greek notions of skies as a big shell has its roots in this line of thinking.

Having said all that, Sloterdijk slowly erects his soft-edged building of sphere-thinking – playfully using, abusing and transforming the criticized topoi. Shell-breaking (and in case of higher animals – birth, with all its supplementary symbolic) is a rupture that initiates creation of another closed space; those close spaces, made by closeness of its inhabitants, are spheres. And they are the spaces in which humans live. The whole project of Spheres is about examination and explanation of re-figuration of (human) spheres, proceeded in constant dialog with different conceptualizations of relation between first, pre-natal, pre-subjective, intense physical and radically intimate spheres and sets of secondary, more or less successfully created ones.