I tend to be skeptical that "the purpose of life is happiness" for several reasons, the main one being that the definition of happiness is vague, imprecise, and more often than not, one tends to mean "I just want to live a pleasant life".
I hear very often the following: “my goal in life is happiness, not wisdom”.
If your ultimate goal is happiness, then you have to be very clear about three things: what you mean by a goal, what happiness really is for you and third, how to achieve it. That is, without the proper knowledge, you cannot know if the "happiness" you arrive to at certain point in time is the happiness that corresponds to your ultimate goal or it is merely a "demo" version of what could lay far beyond.
Another way to see morality is as the set of all truths that relate to our behaviours
or "what we ought to do" when conscious beings are involved.
If the words “good” and “bad”, or “better” and “worse” are to mean something at all, we have to directly relate them to the well-being of conscious creatures.
