But if one could be certain of nothing in dealing with creatures so incalculable as human beings, there were explanations of Blanche Stroeve's behaviour which were at all events plausible. On the other hand, I did not understand Strickland at all. I racked my brain, but could in no way account for an action so contrary to my conception of him. It was not strange that he should so heartlessly have betrayed his friends' confidence, nor that he hesitated not at all to gratify a whim at the cost of another's misery. That was in his character. He was a man without any conception of gratitude. He had no compassion. The emotions common to most of us simply did not exist in him, and it was as absurd to blame him for not feeling them as for blaming the tiger because he is fierce and cruel. But it was the whim I could not understand.
上面节选中,有2个比较部分没搞懂,第一个比较是so incalculable as 为什么不是 as incalculable as ? 第二个比较是as for blaming the tiger,为什么不是as to blame the tiger, 以便和前面(was as absurd) to blame对应呢?
另外,顺便请教老师But it was the whim I could not understand. 强调句为什么少了that ?