6.37 There is no force such as to necessitate one thing’s happening on the strength of another thing’s having happened. There is only a logical necessity.
A somewhat loose translation. Cf. the others. The point is that the only necessity is logical necessity. But what then does ‘necessity’ mean? Is this a denial of physical laws of the form ‘If x then y [must happen]’?
Anscombe (see p. 80) says that this view about necessity is a direct consequence of the picture theory, and seems to think that it has nothing else to be said for it.