(urth) Silk's origin

[Marc Aramini]

I trust Tussah's assertion at face value in a way I don't trust Silkhorn later because many of Silk's later statements about identity are born of either ignorance of denial.  Statements like, "maybe no one understands these things" talking about the celestial mechanics also works to undercut the credibility of certain assertions by the narrators (in the same fashion as saying "I am Horn" when we know he is already fully Silk - he just doesn't understand anything about his condition).  
However, there is no reason to assume Tussah is equally fractured in identity and removed from a position of authority over reality when he says, "the son not of my body" to make the opposite interpretation apply to it - "a genetically related individual" as opposed to "an adopted man I will call son because I came up with the idea of growing him even though we share no genetic material", which to me is the surface reading of that statement.