You never asked me to prove happiness is good. :sarcastic
Either way, I will go through some definitions and explain why happiness is good:
1)
benevolence
n
1. inclination or tendency to help or do good to others;
charity
2. an act of kindness
3. (Historical Terms) (in the Middle Ages) a forced loan or contribution exacted by English kings from their nobility and subjects
Collins English Dictionary Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
2)
charity
n pl -ties
1. (Social Welfare)
a. the giving of help, money, food, etc., to those in need
b. (
as modifier) a charity show
2. (Social Welfare)
a. an institution or organization set up to provide help, money, etc., to those in need
b. (
as modifier) charity funds
3. (Social Welfare) the help, money, etc., given to the needy; alms
4. a kindly and lenient attitude towards people
5. love of one's fellow men[from Old French
charite, from Latin
cāritās affection, love, from
cārus dear]
Collins English Dictionary Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
3)
welfare
n
1. health,
happiness, prosperity, and well-being in general
2. (Government, Politics & Diplomacy)
a. financial and other assistance given to people in need
b. (
as modifier) welfare services
3. (Government, Politics & Diplomacy) Also called
welfare work plans or work to better the social or economic conditions of various underprivileged groups
(Government, Politics & Diplomacy)
the welfare Informal chiefly Brit the public agencies involved with giving such assistance
(Government, Politics & Diplomacy)
on welfare Chiefly US and Canadian in receipt of financial aid from a government agency or other source[from the phrase
wel fare; related to Old Norse
velferth, German
Wohlfahrt; see well1, fare]
Collins English Dictionary Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
Benevolence directly relates with doing charity.
Charity directly relates with promoting welfare.
Welfare and happiness are directly related.
Therefore, considering benevolence is the inclination to do good to others and that through it happiness is intentionally promoted, then we can conclude that happiness is good.