Carl Menger explores what makes something a “good” for an individual and identifies four conditions: a human need, the ability of the thing to satisfy that need, knowledge of its utility, and control over it. The chapter then examines what is the “value” of a good for an individual. It emphasizes that value is subjective, arising from individual needs and perceptions at specific moments, not from inherent qualities of the goods themselves. Key ideas include the law of marginal utility, the imputation principle, and the role of time and opportunity costs in valuation.