Greg Jayne, Opinion page editor The unavoidable reaction is to be revolted. To question the depravity of humanity and to weigh our capacity for inhumanity.A group of young adults in Chicago last week kidnapped a mentally disabled 18-year-old and proceeded to torture him for hours. The captors slapped, kicked, and punched the victim, slashed off part of his scalp, flicked cigar ashes into the wound, made him drink toilet water, and verbally abused him. The perpetrators were black; the victim was white. At least one of the criminals shouted epithets about Donald Trump and white people. Oh, and they streamed a portion of this on Facebook Live.Four suspects have been arrested and charged with a variety of offenses, ranging from kidnapping to hate crimes. It is reasonable to conclude that justice will be served in this case.For anybody who has a modicum of compassion, the video is difficult to watch. Yet, because it arrives at the intersection of race and politics and violence and social media, it is impossible to ignore. Many, many words already have been spoken and written about the torture; many, many tweets already have been tweeted. And while people on both ends of the spectrum have attempted to distort this depravity for their personal political gain, I can’t help but think we will be better for this video coming to the attention of the public.No, not for the gross violence it depicts. Not for the wedge it offers for those who endeavor to divide us along racial lines. Not for the copycat or retaliatory attacks it might inspire. But for the very fact that it illuminates what previously would have been a shadowy incident.The harsh reality provided by the existence of a video makes the evil undeniable, giving life to it in a way that mere words in a newspaper article cannot. And it is only through that illumination that we, as a society, can effectively identify and eradicate such evil.