Leibniz is unclear about the nature of pleasure. In some texts, he describes pleasure as a perception of perfection, while in other texts he describes pleasure as being caused by a perception of perfection. In this article, I disambiguate two senses of “perception of perfection”, which clarifies Leibniz’s considered position. I argue that pleasure is a perception of an increase in a substance’s power which is caused by a substance’s knowledge of a perfection of the universe or God. This reading (...) helps clarify the nature of Leibnizian happiness. Happiness is a cognitive process (akin to a mood), constituted fundamentally out of pleasure, which is grounded in increases in a substance’s power. A rational substance will sustain its happiness so long as it is more powerful than it is weak, and it is engaging in activities that increase its power. (shrink)