Final answer:
Substantive interests can be classified as intrinsic, valued for their own sake, or instrumental, valued as a means to achieve other ends. The study of interests involves the exploration of values, self-interest, and altruism in the context of personal and communal welfare.
Step-by-step explanation:
The blank in the question, 'Substantive interests may be intrinsic, instrumental, or both; we may want something because it is intrinsically satisfying to us a hand or we may want something because it helps us achieve a long-range goal,' should be filled with the words 'intrinsic' and 'instrumental.' The concept of interests here refers to the reasons behind our actions and desires, which can be valued for their own sake (intrinsic) or as a means to achieve something else (instrumental).
Values and well-being are often debated in philosophical circles with opinions ranging from cognitivism, stating that values are cognitive and express statements, to non-cognitivism which suggests that values are more related to psychological states. Individuals can be motivated by a mix of self-interest and altruism, seeking to satisfy their desires for personal well-being or contributing to the community's well-being.