Cogito Ergo - Sum - Cogito Ergo Sum Petoskey Cogito Ergo Sum Is a Northern Michigan Group consisting of two local artists trying to show diversity and versatility through weekly entertainment. This page will post four sounds weekly, Written/Recorded/Posted the day of followed by one Sound posted each Sunday night Written/Recorded over the weekend. All beats will be from local producers. Cogito Ergo - Sum -’s tracks Adrenaline by Cogito Ergo - Sum - published on 2014-03-31T18:25:50Z ipsum by Cogito Ergo - Sum - published on 2014-03-28T21:23:51Z