Just as it is with the human system—the lowly foot is perfect and complete in its place, though inferior in construction and service to the regal head and cunning hand. And should the foot be endowed with the higher gifts it would be a departure from its perfection in organization as related to the whole. The question, then, of the _perfect nature_ of each human mind requires that we regard each one as a part of an infinite system demanding grades and ranks, and thus, also, relative disparities. And having proved that the chief design of the Creator is to make the _best possible_ system, we are necessarily led to the conclusion that the lowest order of mind is as perfect in its nature, in relation to the great whole, as is the highest of all. From the above we gain this definition: _A perfect mind_, as to _construction_ or _nature_, is one which is better fitted to its position in the best _possible_ system of minds than it would be by any possible change. In this use of the words _nature_ and _perfect_ it is claimed that in the preceding pages it has been proved that the mind of man is _perfect in nature_. Our next inquiry will relate to the perfect _action_ of mind in respect to that which is _voluntary_ or _self‐originated_. In other words, we shall inquire as to the _perfect moral action_ of the human mind, as discoverable by reason and experience, independently of revelation. CHAPTER XXII. RIGHT AND WRONG—TRUE VIRTUE. Having discovered the end for which mind is made, and thus gained the idea of what is meant by perfectness, in its _nature_ or _construction_, we next inquire as to what is the perfect _action_ of mind. Here we must again recognize the distinction between two classes of mental actions, viz., those acts which are _natural_ as resulting necessarily from the constitution of mind, of which God is the producing cause, and those which are _voluntary_ and of which man is the producing cause. The first are _natural and involuntary_, the latter are _moral and voluntary_. This introduces the second part of the system of natural religion, that which relates to man’s obligations or duty toward the Creator, toward his fellow beings, and toward himself. In other words, the question is, “what is _right voluntary or moral action_?” In seeking the reply to this without the aid of revelation, the following particulars demand attention: In all discussions on this question there is no mental analysis more important than the distinction between the desire, or what _moves_ us to choose, and the act of choice. The mind is always moved to choice by desire for some good to be gained or some evil to be avoided. The susceptibility or power of being thus led, in popular language is called a “bias,” an “inclination,” a “propensity,” a “tendency,” or a “proclivity” toward the object which causes the desire. Thus the susceptibility to desire stimulating drinks is excited by liquors, and this is called “a propensity” to strong drink.