An Etymological Dictionary of the German Language/denken

by Friedrich Kluge

denken, vb., ‘to think, call to mind, conceive, believe,’ from MidHG. dęnken, OHG. dęnchen, ‘to think, bear in mind, devise, excogitate’; corresponds to Goth. þagkjan (þankjan), ‘to consider, ponder, reflect,’ AS. þęncan. E. to think, is an intermediate form between AS. þęncan, ‘to think,’ and þyncan, ‘to seem.’ Denken is in form a factitive of dünken, which was originally a str. vb., meaning ‘to seem’; ‘to make a thing seem’ is ‘to consider, ponder.’ See dünken.