Revealing, concealing, seeming, appearing, glimpsing and suddenness are topics that ask for further thought when from Hopkins, an author who crosses to and fro over the threshold between literature and philosophical theology, we turn to one who crosses back and forth over the threshold between literature and natural science.

It would be wrong to suppose that the incompleteness we have come to regard as intrinsic to what Hopkins calls inscape can be equated with the incompleteness philosophical phenomenologists like Edmund Husserl attribute to what they call Abschattungen. This term, sometimes translated as ‘shadings’ or ‘offshadings’ or ‘slants’, is introduced by these philosophers to refer to aspects of things that are not currently fully present in perceptual experience but only implied, such aspects as that of the underside of a plate resting on a table viewed from above. Although Hopkins’ word ‘siding’ might seem to be equivalent to ‘aspect’, shadings are what philosophers of the British empiricist and phenomenalist tradition would refer to as possible perceptions. The hidden underside of the plate belongs to the notion of the plate's solidity. The inscape, which is more or less elusive and always changing, is, we have seen, the ‘personality’ of something, including the ‘personality’ of things that are usually contrasted with persons. This is closer to what classical medieval philosophy stemming from Aristotle calls essence, except that essence is what is given in a definition employing common nouns and universal predicates, whereas the inscape is sensorily ‘glimpsed’ or otherwise ‘sensed’. Here ‘sensing’ implies more guesswork than what Husserl calls protensions, meaning by this the proleptic reference to incipient shadings or aspects. What is ‘sensed’, we could say, taking the hints from John Grote and Bertrand Russell noted earlier, is that with which we have ‘quaintance’, keeping the allusion ‘quaint’ makes to the singular strangeness, idiosyncraticness and ‘peculiarity’ to which Hopkins believes himself duty-bound as poet to give voice. What is ‘sensed’ takes us more or less by surprise. It does not belong simply to the sphere of verifiable possible perception constitutive of the nature or essence of a thing.