What is the definition of a theory? There are many possible ways to define a theory. Below is one possible theory definition. I believe that this can be viewed as a definition of a scientific theory, and it may be helpful in thinking about ideas about feeling, thinking, and human behavior.
A theory can be viewed as a general idea or a set of related ideas that may help to explain events, phenomena, behaviors, or research findings.
Not every idea should be consider a theory. Some ideas may be too specific to be described as a complete theory. An idea that is fairly general and explains much could be considered a complete theory. For example, an idea that can explain many behaviors, or a behavior in many situations, could be considered a complete theory. Frankl (1992) suggested that the search for meaning is a primary motivation. This idea could be labeled as a theory. It is a general statement that may explain many behaviors.
Sometimes the combination of related or connected ideas can be viewed as a theory. It can be considered a theory because the combination of the ideas may explain a sufficient number of behaviors. For example, we develop a theory of intelligence that involves specific types of intelligence, and how these types of intelligence influence certain motives.
References
Frankl, V. E. (1992). Man's Search for Meaning: An
Introduction to Logotherapy. (4th edition). Boston:
Beacon Press.