'On Human Nature' by Arthur Schopenhauer covers the topics of Human Nature, Government, Free-Will and Fatalism, Character, Moral Instinct, and Ethical Reflections. The book begins by noting the significant difference between things and life, more than external significance, what separates life is its internal significance. How one needs to be very careful in identifying virtue or naming vice. For example, Diligence, Obedience, Justice and Humility can become an instrument of virtue; also the servant of the greatest villainy.
I liked the observation, with which the book begins. "When philosophers are called upon to explain those simple relations of human life which make up the substance of this right, such as Right and Wrong, Property, State, Punishment and so on, they have recourse to the most extravagant, abstract, remote and meaningless ideas." As can be expected, the ideas presented in this book, about, the nature and formation and necessity of governments, free-will fatalism, character, etc., dwell more on the practical necessity and relevance of these concepts for human life rather than an abstract discussion. For example, "State is needed in human life, since 'wrong is the order of the day'. Or the reflections on honour, "Although the principle of honour is something which distinguishes man from the lower animals, it is not, in itself, anything that raises him above them". It is just a good excuse for tolerating something inconvenient.
I find this book, unlike the works of all philosophers I have read, rather than giving a finality of an answer, prompts serious reflections.