Who is John Howard Lawson from The Art of Dramatic Writing and what is their importance?

Looking at John Howard Lawson's book on writing, The Theory and Technique of Playwriting, the author finds he is in compliance with Aristotle's opinion that character is secondary to action, but then finds him contradicting this shared belief later on in his book. The author also disagrees with Lawson's idea that situations are tough to come by and that a great imagination is needed to strain out some good ones. Conversely, the author believes "situations are inherent in the character."