There is much caution needed in speaking of this. There are causes which lead to spiritual depression which are purely physical, arising from a diseased body, an overstrung mind--a succession of calamities weakening and impairing the nervous system. We know how susceptible are the body and mind together, of being affected by external influences. "We are," says an able analyser of human emotions, "fearfully and wonderfully made. Of that constitution which in our ignorance we call union of soul and body, we know little respecting what is cause, and what effect. We would fain believe that the mind has power over the body; but it is just as true that the body rules the mind. Causes apparently the most trivial--a heated room, want of exercise--a sunless day, a northern aspect--will make all the difference between happiness and unhappiness; between faith and doubt; between courage and indecision. To our fancy there is something humiliating in being thus at the mercy of our animal organism. We would fain find nobler causes for our emotions."[13] Yes--many of those sighs and tears, and morbid, depressed feelings, which Christians speak of as the result of spiritual darkness and the desertion of God, are merely the result of physical derangement, the penalty often for the violation of the laws of health. The atmosphere we breathe is enough to account for them. They come and go--rise and fall with the mercury in the tube. These are cases, not for the spiritual, but for the bodily physician. Their cure is in attendance to the usual laws and prescriptions which regulate the healthy action of the bodily functions. [13] Rev. Fred. Robertson's "Sermons; Second Series," p. 85. There is another class of causes which lead to spiritual depression which are partly physical and partly religious. There must necessarily be depression where there is undue elation; where the soul-structure is built on fluctuating frames and feelings, and the religious life is made more _subjective_ than _objective_.