'Tis by no means impossible, but that all the several Colours we see, when involved in a Shadow, may equally lose their different Lustres, and appear transform'd into the single Colour of the Shadow it self: This in effect is no more than what happens every dark Night, during which, we are unable to distinguish either the Figure, or the Colour of any Body whatever: For darkness being nothing but a mere privation of all Light, both incident and reflected, by means of which we discern the Forms and Colours of Objects; it follows that the cause being taken away, the effect must cease of course.