It is based on the insist that people are motivated by please are to avoid pain, and that people rationally make life decisions
Benetham, today would be considered a 'scoial scientst' starting form a top-to-bottom approuch: looking how people behve and what motives them to make choices -both for themselves and those they care about.
"Nature has placed mankind under the governence of two sovereign masters, pain and pleasure,... they given us in all we do, in all we say, in all we think."