XI. The limit, however, thus determined, is an ultimate one, and it is well in all things to be cautious how we approach the utmost limit of lawfulness; so that, although the employment of metal within this limit cannot be considered as destroying the very being and nature of architecture, it will, if, extravagant and frequent, derogate from the dignity of the work, as well as (which is especially to our present point) from its honesty. For although the spectator is not informed as to the quantity or strength of the cement employed, he will generally conceive the stones of the building to be separable and his estimate of the skill of the architect will be based in a great measure on his supposition of this condition, and of the difficulties attendant upon it: so that it is always more honorable, and it has a tendency to render the style of architecture both more masculine and more scientific, to employ stone and mortar simply as such, and to do as much as possible with the weight of the one and the strength of the other, and rather sometimes to forego a grace, or to confess a weakness, than attain the one, or conceal the other, by means verging upon dishonesty. Nevertheless, where the design is of such delicacy and slightness as, in some parts of very fair and finished edifices, it is desirable that it should be; and where both its completion and security are in a measure dependent on the use of metal, let not such use be reprehended; so only that as much is done as may be, by good mortar and good masonry; and no slovenly workmanship admitted through confidence in the iron helps; for it is in this license as in that of wine, a man may use it for his infirmities, but not for his nourishment.