To get an insight of what realism and liberalism is all about four (4) questions must be asked and answered and before asking- What is Liberalism/Idealism? Those questions are: what is a theory? Why theories are necessary? What is hypothesis? And how many types of theories are there? All these questions will give basic knowledge about the three theories of international relations; but the topic sets a limit to how many theories to cover and that theory is liberalism/idealism.
What is a theory? According to gavilan, a theory simplifies reality. It is a perspective which tells you where to look. A statement of cause and effect/outcome- what correlates? Why does this regularity occur? The cause and effect underlined above implies the independent or explanatory variable and dependent variable respectively.
Why are theories necessary? (1) Too much information available to be able to process it without guidance about what is relevant or irrelevant. (2) No rational action without hypothesis about cause and effect.
What is hypothesis? Every theory brings out hypothesis. A hypothesis is a testable implication of a theory. Evidence supports a theory but does not prove it.
How many types of theories are there? There are three major theories; these theories are: Realism, Liberalism, and Constructivism. Constructivism is divided into Marxism and Post- modernism and Post- structuralism.
After knowing all these, the question- what is idealism/liberalism? Can be asked, but, due to the relation of liberalism/idealism with reciprocity principle the definition of collective goods problem should be stated. Collective good problem is how a group of nations serve the/its group interest or collective interest by doing so members to forfeit their individual interest. In other words, it is the problem of shared interest versus competing interest. It solves the problem of how to