Philotas’ “Conspiracy”

“Then the persons who had reported the affair came forward, with various irrefutable proofs of his own guilt and that of his fellow-conspirators, of which the most damning was that he had admitted knowledge of a plot against Alexander but had said nothing about it.”
(Arrian 3.26.2)

Explain why Arrian comes to this conclusion about Philotas’ “conspiracy”, and assess the relative value of the source tradition for the episode.

“Then the persons who had reported the affair came forward, with various irrefutable proofs of his own guilt and that of his fellow-conspirators, of which the most damning was that he had admitted knowledge of a plot against Alexander but had said nothing about it.”
(Arrian 3.26.2)

Explain why Arrian comes to this conclusion about Philotas’ “conspiracy”, and assess the relative value of the source tradition for the episode.

        There have been various suggestions put forward as to Philotas’ involvement in the conspiracy that lead to his execution or murder[1]. They range from him being an innocent bystander guilty only of neglecting to report information to Alexander through to an active participant in the conspiracy. The reasons for his neglecting to pass the information on to Alexander are also varied from not taking it seriously to passively condoning the conspiracy and waiting to see the outcome. There are equally as many suggestions as to why the Affair ended in his death. Was it a conspiracy on Alexander’s part to rid himself of the House of Parmenion ? A conspiracy by or an opportunity taken by a group of Philotas’ enemies - Hephaestion, Craterus, Coenus, Erygius, Perdiccas, Leonnatus - to rid themselves of him and thereby open up advancement for themselves ? Or was it simply that he was guilty either of being actively involved in the conspiracy or passively waiting to see the outcome ?
        Arrian makes it clear at the start of Book One that he uses both Ptolemy and Aristobulus as his main sources. He explains...