Convergent and divergent thinking were first recognized by J.P. Guilford. He observed that most people prefer either convergent or divergent types of thinking. J.P. was a psychologist who also developed a psychometric study of human intelligence and proposed that three dimensions were necessary for accurate descriptions that included content, operations, and productions.
Convergent thinking involves the ability to gather thoughts using a variety of different sources to fix a problem in such a way as to produce the correct answer. Convergent thinking works very well when dealing with science, math, and technology. With convergent thinking there is a need for consistency and reliability. It relies on speed, accuracy, and logic. Convergent thinking involves what a person may already know, rather than developing their own solutions.
Divergent thinking involves creativity. This way of thinking is better suited for artistic pursuits and the study of humanities. Divergent thinking encourages people to develop their own solutions to problems, thus making them more resourceful.
There is also the act of reasoning. Reasoning involves the capacity of people to make sense of things, to verify facts, and to change the way they do things. There are two types of reasoning, inductive and deductive. Inductive is described as moving from the specific to the general and deductive moves the opposite, from the general to the specific. Arguments based on experiences or observations should be expressed inductively and ones based on rules, laws, or accepted principles should be expressed deductively.
References:
Atherton J S (2011) Learning and Teaching; Convergent and Divergent Learning [On-line: UK] retrieved 9 October 2011 from http://www.learningandteaching.info/learning/converge.htm
San Jose State University Critical Thinking Education Department.