Prof. Nelson Sizer says: "It gives ability to look deeply into subjects, and to appreciate the logical sequences of arguments, hence it is large in persons who indicate genius in metaphysics, political economy, and all sciences of a profound character.... When prominent, and the perceptive faculties are moderate, and Comparison (Analysis) is not equally influential, it tends to speculative thinking. Men so constituted are given to spinning improbable theories; their notions are too abstract for ordinary minds, and they are looked upon as dull and heavy weights in society. On the other hand when it (Logic) is deficient, the individual is superficial and incapable of taking comprehensive views of subjects; or forming judgments that will apply to the affairs of life successfully." Professor O. S. Fowler says that this Quality gives "the desire to know the _why and wherefore_ of things, and to investigate their laws; ability to reason from causes down to effects, and from effects up to causes; the therefore and wherefore; ability to adapt ways and means to ends, to plan, contrive, invent, create resources, apply power advantageously, make heads save hands, kill two birds with one stone, predict the results of given measures, etc." This Quality manifests outer form in the sides of the upper part of the forehead, one either side of Analysis and over Locality (see group figure). When large it gives to the forehead a "high, bold, square" form. With large Perceptives this Quality does not present so prominent an appearance and so marked a comparison, but with the Perceptives small it gives to the brow an "overhanging" appearance. With Analysis equally, or nearly as strong, the fullness of course extends well across the forehead; but with Analysis much smaller, Logic presents a bulging on each side of the forehead; while with Analysis large and Logic small, the latter gives the appearance of two depressions on each side of the forehead. Spurzheim well says of the combination of Analysis and Logic (which he terms "Comparison" and "Causality," respectively): "Causality and Comparison combined constitute Reason. Without Causality (Logic) there can be no argumentative reasoning; without Comparison (Analysis), no comprehensive views, and no nice distinctions. Observation teaches objects, and Eventuality facts, while Comparison (Analysis) points out their identity, analogy, difference or harmony, whereas Causality (Logic) seeks their causes, and all together discern general principles and laws; draw conclusions, inductions and creations, and constitute a truly philosophical understanding." CHAPTER XV THE RELIGIO-MORAL QUALITIES The tenth group is known as the Religio-Moral Qualities, and is composed of the following particular Qualities: _Reverence_, _Mysticism_, _Optimism_, and _Conscientiousness_, respectively. This group manifests outer form at the front-top of the head, and on either side thereof (see Fig. 11).