In Itself

At first, 'in itself' means for Kant 'independent of other entities', while later, it means 'internal'.  As he systematizes the two usages, there is no equivocation involved, since the former is a 'negative' correlate to the latter, which is 'positive', e. g. 'independent of being perceived' to 'rational process'.  However, the correlation is not exact, for, the first does not exclude external surfaces, while the second does.  That is, the shift from the first usage to the second effects a severing of outer from inner, which means that, on the basis of the second meaning, an entity 'in itself' can possess no instinct to emerge from privacy to appear to others.  In other words, on the second meaning, which is the prevalent one for both Kant and Schopenhauer, a human being does not possess an inherent instinct to socialize.