It would be difficulty to express it accurately and concisely, but here is my attempt:
Plato held that (1) the pursuit of pleasure could not be the best mode of life, because (2) pleasure has no limit--and (3) having no limit, the pursuit of limitless pleasure ends in wickedness.
(4) Virtue is the way to correct wickedness, (5) and Divine Law is the supernatural check against the heedless pursuit of pleasure.
But Epicurus thought (1) that the pursuit of pleasure was the best mode of life, because (2) the limit of the quantity of pleasure is the removal of all pain--and (3) culminating in the removal of all pain, the pursuit of pleasure does not lead to wickedness. (4) The wicked bring pain on themselves, (5) and pain is the natural check against the heedless pursuit of pleasure.