But first I will quote from Sir Martin Conway the explanation of what Dürer means by the phrase, "Words of Difference."
These are what he calls the "Words of Difference": large, long, small, stout, broad, thick, narrow, thin, young, old, fat, lean, pretty, ugly, hard, soft, and so forth; in fact any word descriptive of a quality "whereby a thing may be differentiated from the thing (normal figure) first made."
Or, as Dürer says in another place, "difference such as maketh a thing fair or foul."
But further, it lieth in each man's choice whether or how far he shall make use of all the above written "Words of Difference." For a man may choose whether he will learn to labour with art, wherein is the truth, or without art in a freedom by which everything he doth is corrupted, and his toil becometh a scorn to look upon to such as understand.
Wherefore it is needful for every one that he use discreetness in such of his works as shall come to the light Whence it ariseth that he who would make anything aright must in no wise abate aught (that is essential) from Nature, neither must he lay what is intolerable upon her. Howbeit some will (by going to an opposite extreme) make alterations (from Nature) so slight that they can scarce be perceived. Such are of no account if they cannot be perceived; to alter over much also answereth not. A right mean (in such alterations) is best. But in this book I have departed from this right mean in order that it might be so much the better traced in small things. Let not him who wishes to proceed to some great thing imitate this my swiftness, but let him set more slowly (gradually) about his work, that it be not brutish but artistic to look upon. For figures which differ from the mean are not good to look upon when they are wrongly and unmasterly employed.
It is not to be wondered at that a skilful master beholdeth manifold differences of figure, all of which he might make if he had time enough, but which, for lack of time, he is forced to pass by. For such chances come very often to artists, and their imaginations also are full of figures which it were possible for them to make. Wherefore, if to live many hundred years were granted unto a man who had skill in the use of such art and were thereto accustomed, he would (through the power which God hath granted unto men) have wherewith daily to mould and make many new figures of men and other creatures, which none had before seen nor imagined. God, therefore, in such and other ways granteth great power unto artistic men.
Although there be such talking of differences, still it is well known that all things that a man doth differ of their own nature one from another. Consequently, there liveth no artist so sure of hand as to be able to make two things exactly alike the one to the other, so that they may not be distinguished. For of all our works none is quite and altogether like another, and this we can in no wise avoid.
We see that if we take two prints from an engraved copper-plate, or cast two images in a mould, very many points may immediately be found whereby they may be distinguished one from another. If, then, it cometh thus to pass in things made by processes the least liable to error, much more will it happen in other things which are made by the free hand.
This, however, is not the kind of Difference whereof I here treat; for I am speaking of a difference (from the mean) which a man specially intendeth, and which standeth in his will, of which I have spoken once and again....
This is not the aforesaid Difference which we cannot sever from our work, but, such a difference as maketh a thing fair or foul, and which may be set forth by the "Word of Difference" dealt with above in this Book. If a man produce "different" figures of this kind in his work, it will be judged in every man's mind according to his own opinion, and these judgments seldom agree one with another.... Yet let every man beware that he make nothing impossible and inadmissible in Nature, unless indeed he would make some fantasy, in which it is allowed to mingle creatures of all kinds together....