As Husserl argues in the fifth Cartesian Meditation, the similarity of my B
ody (Leib) with the body (Korper) of another person is the founding moment
of th experience of the other. This similarity is based on the previous obj
ectivation of my Body. Husserl continuously worried to explicate this simil
arity-premise and by doing so, it appeared that this objectivation already
presupposes intersubjectivity. By running into this problem, the Meditation
actually fulfills its program by showing that the other is co-constitutive
of the world and more precisely of my existence as a worldly human being.
At the same time he developed an alternative approach by identifying the or
iginal experience of the other as an expressive unity (Ausdruckseinheit) as
the condition of possibility of intersubjective experience. By drawing on
the relevant Forschungsmanuskripte in the volumes on Intersubjectivity and
on Ideas II, it appears that the Meditation offers a naturalistic theory of
intersubjectivity that results from the introduction of the reduction to p
rimordiality. When one takes into account Husserl's analysis of the experie
nce of an expressive unity, that is a defining characteristic of the person
alistic attitude, one can clarify the derivative nature of this naturalisti
c approach.