logicien

from the Indo-European root *leg, in ancient Greek legein (and its family) 'to gather', hence 'to say'. The Greek words are related: logos 'speech', 'discussion', 'reason'; logikos 'concerning speech', 'concerning reasoning'. On this basis, various learned medieval French words were created: logique (13th century) 'art of reasoning', and logicien (13th century); hence the adverb logiquement (18th century)