Frankenstein中的一句话

The circumstance on which my story rests was suggested in casual conversation. It was commenced (开始,着手) partly as a source of amusement, and partly as an expedient (应急手段，an action that achieves a particular purpose) for exercising any untried resources of mind.
Other motives were mingled with these as the work proceeded.
I am by no means indifferent to the manner in which whatever moral tendencies exist in the sentiments (情绪) or characters it contains shall affect the reader; yet my chief concern in this respect has been limited to the avoiding of the enervating (make you tired and week) effects of the novels of the present day, and to the exhibitions of the amiableness (和蔼可亲) of domestic affection, and the excellence of universal virtue.
These tales excited in us a playful desire of imitation.