My body is my body and not my body's body. So I am not my body. I have a body. This having, presumably sui generis and unlike any other type of having, is yet a having and not a being. My body doesn't have a body. I know that I have a body. My body doesn't know this. So again I am not my body. 'This body is this body' is a tautology. 'I am this body' is not a tautology.
The human body is not a body in the sense of physics alone but an embodiment of subjectivity. The body of the Other is the body of the Other.
Contra Husserl: I cannot constitute Paul's body (Leib, nicht Koerper) as a lived body without first constituting him as an Other Mind. So I cannot explain the constitution of the Other as Other by starting from the constitution of the body. The Fifth of the Cartesian Meditations ends in shipwreck.