It would be pretty odd to say "That car is nice, in that it is blue" unless you were speaking to someone who knew that you had a (probably extreme) predeliction for the colour blue.

I don't quite agree with @Robusto's implication that because can't substitute for in that. It often can, in that/because there's often no real difference between whether the statement preceding it is something literally caused by the 'subsidiary statement' following, or "metaphorically" comes to be true from the perspective of the subsidiary.

To my mind, the primary difference is that in that is a somewhat "formal" construction, primarily used in writing rather than speech.

A secondary difference concerns the fact that, as Robusto says, it can usually be replaced by in the sense that. If it seems reasonable in context to replace by only in the sense that, you almost certainly couldn't use because instead.

It would be pretty odd to say "That car is nice, in that it is blue" unless you were speaking to someone who knew that you had a (probably extreme) predeliction for the colour blue.

I don't quite agree with @Robusto's implication that because can't substitute for in that. It often can, in that/because there's often no real difference between whether the statement preceding it is something literally caused by the 'subsidiary statement' following, or "metaphorically" comes to be true from the perspective of the subsidiary.

To my mind, the primary difference is that in that is a somewhat "formal" construction, primarily used in writing rather than speech.

A secondary difference concerns the fact that, as Robusto says, it can usually be replaced by in the sense that. If it seems reasonable in context to replace by only or specifically in the sense that, you almost certainly couldn't use because instead.