B4;C42
In many ways Mr. Casaubon is already dead, he’s just waiting around for his body to catch up with that knowledge.
Eliot is drawing comparisons between Mr. Casaubon who lives only for scholarly pursuits and has no life in him, to Fred who lives plenty yet has no sense. Both are being disappointed through disillusionment (Mr. Casaubon with marriage, Fred through not getting the money). Eliot begs for balance.