Touching my works you shall, before everything else, receive the thirteenth volume.  It is very kind of you not to neglect the Theory of Color; and the fact that you absorb it in small doses will have its good effect too.  I know very well that my way of handling the matter, natural as it is, differs very widely from the usual way, and I cannot demand that every one should immediately perceive and appropriate its advantages.  The mathematicians are foolish people, and are so far from having the least idea what my work means that one really must overlook their presumption.  I am very curious about the first one who gets an insight into the matter and behaves honestly about it; for not all of them are blindfolded or malicious.  But, at any rate, I now see more clearly than ever what I have long held in secret, that the training which mathematics give to the mind is extremely one-sided and narrow.  Yes, Voltaire is bold enough to say somewhere:  “I have always remarked that geometry leaves the mind just where it found it.”  Franklin also has clearly and plainly expressed a special aversion to mathematicians, in respect to their social qualities, and finds their petty contradictory spirit unbearable.

As concerns the real Newtonians, they are in the same case as the old Prussians in October, 1806.  The latter believed that they were winning tactically, when they had long since been conquered strategically.  When once their eyes are opened they will be startled to find me already in Naumburg and Leipzig, while they are still creeping along near Weimar and Blankenheim.  That battle was lost in advance; and so is this.  The Newtonian Theory is already annihilated, while the gentlemen still think their adversary despicable.  Forgive my boasting; I am just as little ashamed of it as those gentlemen are of their pettiness.  I am going through a strange experience with Kugelchen, as I have done with many others.  I thought I was making him the nicest compliment possible; for really the picture and the frame had turned out most acceptably, and now the good man takes offence at a superficial act of politeness, which one really ought not to neglect, since many persons’ feelings are hurt if we omit it.  A certain lack of etiquette on my part in such matters has often been taken amiss, and now here I am troubling some excellent people with my formality.  Never get rid of an old fault, my dear friend; you will either fall into a new one, or else people will look upon your newly acquired virtue as a fault; and no matter how you behave, you will never satisfy either yourself or others.  In the meantime I am glad that I know what the matter is; for I wish to be on good terms with this excellent man.