During Aristotle’s times, happiness was seen as something temporary and confused with different feelings. In reality, happiness is a feeling that is not measurable and needs to be always present. That is the default setting in nature. Human beings need to coexist with everything else in nature and be in alignment and happiness will be permanent.
Happiness is mostly misunderstood with different feelings like contentment, pleasure, excitement, epiphany, abundance, belonging, achievement, success, etc. These are all in some way connected to happiness but do not constitute complete happiness. A human being is a blend of a life-atom or soul which adopts a physical body to gain enlightenment. The body needs nourishment and protection. The soul needs understanding and experiencing through the physical body. Once both their needs are fulfilled, then the feeling that follows is actual happiness.