When primeval man first used flint stones for any purpose, he would have accidentally splintered them, and would then have used the sharp fragments. From this step it would be a small one to break the flints on purpose and not a very wide step to fashion them rudely.
Charles Darwin (1874). “The Descent of Man, and Selection in Relation to Sex ... Second Edition, Revised and Augmented, with Illustrations. Tenth Thousand”, p.82
