Flacksenius, Jacobus a Finnish theologian and physician, a native of Mackylad, was provost of the cathedral of Abo. In 1665 he taught logic and metaphysics in that same city; in 1679 he lectured on theology, and died in 1696, leaving, Institutiones Pneumaticae (Abo, 1664): — Colleqium Logicum, (ibid. 1678). See Hoefer, Nouv. Biog. Generale, s.v.