Perelman

Premise/Argument	Quote
Premise-Facts/Truths—(Supposed)	“The world of Ripperology is surrounded by suspects, who appear to walk out of the shadows and into the scrutiny of the eyes of Ripperologists, with alarming frequency. Yet some suspects attract more attention than others. Furthermore, a select group appear to court controversy, usually due to the shoddy nature of their candidature. These are suspects like Gull, Maybrick and, more recently, Sickert, who have attracted a high degree of controversy and promoted research and discussion (sometimes among select groups of Ripperologists) in order to dismiss them from the suspect list. Of these controversial suspects, one stands out, and he is Robert D’Onston Stephenson[1]. This is because he has created animosity amongst Ripperologists without ever having truly captured the popular imagination of the wider public as a genuine Ripper suspect. He has been the subject of Ripper theories by two published authors Melvin Harris and Ivor Edwards”
Premise Modifiers-Enthymeme	“In Jack the Ripper the Bloody Truth[2] Harris stated that he felt ‘in truth only one man can be seriously considered as Jack the Ripper. That man is Doctor Roslyn D'Onston’. Harris’s view of D'Onston’s candidacy as the best Ripper remained unchanged from this point throughout his life and was researched further for his two subsequent books. In The Ripper File[3] Harris stated that he aimed to ‘assemble my new findings and draw a fresh portrait of the man [D’Onston] himself’[4]. Harris’s subsequent book True Face of Jack the Ripper[5] was his main suspect book and served as a portrait of the man who he believed was the killer; in it Harris outlined his theory in its most complete form.”
Premise-Presumptions—(The likely)	“‘alone, of all the suspects, had the right profile of the opportunities, the motives, and the ideal cover. His background, his personality, his skills, his frame of mind, all [point to] him for the fateful role.”
Argument-Quasilogical—(Division)	In sum, the suspect Robert ‘Roslyn’ D’Onston Stephenson is an interesting one. He associated himself with the murders by being an early Ripperologist and attempting to put forward theories as to why the Ripper killed and who he was. This was sufficient for him to draw attention to himself at the time in both the eyes of George Marsh and W.T. Stead; in the way his knowledge of the murders was perceived to be too accurate by both men. However, against the idea of his candidature, are, most importantly, that the police appear to have dismissed the idea at the time (even though Roots apparently knew D’Onston). Also, against the idea are some of the theories behind how he would have managed to do it (faked illness) and why (black magic). However, readers must be reminded that theories in themselves can be wrong whilst a suspect can be perfectly legitimate. It is for readers to investigate further and decide where they nail their colours and why.