Conversation so far:
What is the relation between Raymond Cattell and Factor analysis?
In the 1920s, Raymond Cattell worked with Charles Spearman, who was developing the new statistical technique of factor analysis, in his effort to understand basic dimensions and structure of human abilities.
What is the purpose of the effort of factor analysis applied?
Raymond Cattell postulated that factor analysis could be applied to other areas beyond the domain of abilities.

Question: How do they come about with the factor analysis?
Self-contained rewrite: How do Raymond Cattell and Charles Spearman come about with the factor analysis?