Clive had come to this point theoretically, and Maurice instinctively

This really sums up part of the reason I think Clive and Maurice are so unsuited to one another. Maurice is not a great thinker, and what he admires is action. Clive, on the other hand, is all mysterious explanations through Greek writings that are far too obscure for someone like Maurice.

Even if they had got together, I think Clive would have got fed up with Maurice's lack of intellectuality, and Maurice would be pining for some physical movement in their relationship.