A marked dissimilarity exists between three techniques employed in destructive analysis. These methods, sounding, sampling, and core analysis, do not have the same prominence when they are used on, for example, a statue or a large-sized repetitive work. It is therefore the object under study to define the limits of destructive analysis. The methods of nondestructive analysis recommended by the Charter of Venice are today the subject of accelerated development. They may be classified as follows: 1) external analysis; 2) mensurations of and test conditions simulated on models; 3) internal mensuration (radiography, infrared, and sonic scanning). They can be employed not only diagnostically but also as a mean of control during and at the termination of work. Destructive and nondestructive analyses are complementary, the methods of one serving as a base for the verification and standardization of the other. Prudence is necessary for there is a risk that too great an abstraction in analytical techniques might lead to a diminution in the field of interpretation. The need of deductive reasoning becomes more and more evident when one considers the monument as a whole wherein the reply to the problem of its structure must satisfy, at one and the same time, the objectives of good presentation and utility.