State what hedonism consists in and explain one objection that could raised against this view

Do you mean psychological hedonism or ethical hedonism? It is important to make a distinction between the two. Psychological suggests a disposition, while ethical hedonism suggests that everyone should practise this disposition.

We are all hedonistic to a certain degree.It is only our morals that keep us in check. In my opinion.
It is mans nature to please himself.