Ethics (via Latinethica from the Ancient Greekἠθική [φιλοσοφία] "moral philosophy", from the adjective of ἤθοςēthos "custom, habit"), a major branch of philosophy, is the study of values and customs of a person or group. It covers the analysis and employment of concepts such as right and wrong, good and evil, and responsibility. It is divided into three primary areas: meta-ethics (the study of the concept of ethics), normative ethics (the study of how to determine ethical values), and applied ethics (the study of the use of ethical values).
The concept of free will is whether, and in what sense, rational agents exercise control over their actions and decisions. Addressing this question requires understanding the relation between freedom and cause, and determining whether or not the laws of nature are causally deterministic. The various philosophical positions taken differ on whether all events are determined or not - determinism versus indeterminism - and also on whether freedom can coexist with determinism or not - compatibilism versus incompatibilism. So, for instance, hard determinists argue that the universe is deterministic, and that this makes free will impossible.