He saw his situation quite clearly; he had no doubts about it.

If Josephine would come to him and be his wife, he would be happy and prosperous.

Josephine had the power to make him twice the man he was without her.

It was not only that his happiness was bound up in her; it was not only that Josephine had money and could manage it well, although he was not at all above thinking of that; it was not even that she would help and encourage and console him as no one else would.
There was that subtle something, more often the fruit of what is called friendship than of love, by which Josephine's presence increased all his strong faculties and subdued his faults.

Caius knew this with the unerring knowledge of instinct.