Do fat cells function as an endocrine gland?

Yes

Explanation:

Fat cells occur mainly under the skin, performing functions of energy reserve, protection against mechanical shocks and thermal insulation. It also occurs around some organs such as the kidneys and the heart.

Endocrine glands are those that release their secretions (hormones) directly into the bloodstream or lymphatic vessels.

Fat cells can act as an endocrine gland because, by accumulating an amount of fat, these cells begin to produce lipin which is a hormone that acts on the hypothalamus and causes appetite to decrease.

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.