'In particular, it should not be forgotten that the division into embryology, anatomy, physiology, psychology, sociology and clinical medicine does not exist in nature.'
(Quoted by Lacan, in Ecrits)
The elementary point here being that the categories of the understanding are never simply ‘given’ in the object understood. Indeed, it is the scandalous power of the understanding to sunder (and thus render intelligible) what had been (apparently) whole and entire. The categories of the understanding are arrived at, with taxing labour, against the grain of what merely appears. The form of and relations between these categories may be radically at variance with the contours of their object. Thus, understanding first quarters and ‘destroys’ (‘murders’) the thing in order to divulge its meaning, which then stands separate and complete like the prize of plunder. This is, in part, why ‘beauty hates the understanding’ - the necessary violence of knowledge.
At the same time, knowledge also depends on its mimetic moment, in which rewards are won only through absorbed contact with the object itself and patient surrender to its inherent form. Here thought 'penetrates into the immanent content of the matter'. Knowledge needs always to pass through this detour of selfless tact, whereby its forms are bent out of true by the shapes of what refuses its clutch.
Thus, these two moments, violence and tact have to be held in the balance, and the attainment of this balance would be justice of knowledge.