Idealist thinkers consider realism to be morbid and cynical. Idealism is not a united school of thought but is rather a term used to describe the general outlook of liberals, federalists, institutionalists, pacifists, and others. Writers such as Jean-Jacques Rousseau, Mohandas Ghandi, and Woodrow Wilson are considered idealistic. They saw politics as the art of good government, rather than the anarchical power battle envisioned by realists. Idealists think that good political leaders should do what is just, making this an inherently normative doctrine.

Idealists disagree with the idea that conflict and power politics are inevitable or a fundamental part of human nature. They believe in the principle of obedience to legitimate rule and respect for human beings. Another fundamental idealist concept is the changeable nature of human behaviour. Rather than being condemned to violence and strife, they see man as capable of living co-operatively in peace. Incremental change and compromise are possible. Idealist, and especially liberal, theorists focus on the mutual benefits that arise from interdependence and reciprocity.

Assumptions behind idealist thought include:
1. Humans are capable of being co-operative and altruistic.
2. A fundamental human concern for the welfare of others makes progress possible.
3. International relations are not purely dominated by self-interest and power.
4. Bad behaviour is not the product of a wicked human nature, but rather of institutions and structural arrangements which motivate people to act that way.
5. War is not inevitable.
6. War and injustice are international problems that require collective, multilateral action.
7. International security can arise from a re-organisation of international institutions.
8. Win-win scenarios are possible: politics is not a zero sum game.