Miklós Erdély’s life strategy that questioned and kept his art in motion had its last great artistic period at the turn of the 1970s and 1980s: the conventional notions and symbols of philosophy, religion, mathematics, etc., as parts of a “montage”, appear as visual elements mobilizing sensual effects. √-1 is the enigmatic and emblematic key work of the period, the momentary diagnosis of our “world and fate”. The main theme is Erdély’s oft painted “identification mark” which – removed from reality – hoists the spectator beyond the original field of interpretation. The “signs”, motifs sown amidst barely manipulated materials and surfaces, attract new semantic fields: the negative gesture of turning it upside down and the qualifying gesture of endowing it with the minus sign, as well as by the confrontation with the mirror image or with absence. The oscillation of different meanings that mutually cancel out each other, their “communication” requires the active participation of the spectator: stepping back the eye corrects what needs correcting, stepping close, memory, fancy and the emotions eliminate the flaws.