The supplement adds itself, it is a surplus, a plenitude enriching another plenitude, the fullest measure of presence. 

But the supplement supplements. It adds only to replace. 

It intervenes or insinuates itself in-the-place-of; if it fills, it is as one fills a void. 

If it represents and makes an image, it is by the anterior default of a presence. 

The sign is always the supplement of the thing itself. 

The supplement will always be the moving of the tongue or acting through the hands of others. 

In it everything is brought together: Progress as the possibility of perversion, regression toward an evil that is not natural and that adheres to the power of substitution, that permits us to absent ourselves and act by proxy, through the hands of others. Through the written. 

This substitution always has the form of the sign. The scandal is that the sign, the image, or the representer, become forces and make "the world move". 

Blindness to the supplement is the law. 

-Jacques Derrida