The Spirits are created simple and ignorant, but with aptitudes for progress and perfection, by virtue of their free will. Through progress they gain new knowledge, new faculties, new perceptions, and consequently new enjoyments, which are unknown to inferior spirits. They see, hear, feel and understand what backward spirits cannot see or hear, what they cannot feel or understand.

Happiness is related to the progress made; so that, of two spirits, one of them may not be as happy as the other, merely because he has not attained the same intellectual and moral advancement, without each needing to be in a different place.

Though they are together, one may be in the midst of darkness, while around the other everything is shining, just as a blind man and one endowed with sight may hold hands, and the latter perceives the light of which the former does not receive the slightest impression.

Since the happiness of spirits is inherent in their qualities, they can find it wherever they are, whether on the surface of the Earth, in the midst of the incarnate, or in space.

A simple comparison will allow us to understand this situation even better. Let us suppose that two men meet at a concert. One of them is a good musician and has a good ear, and the other has no musical training, and his sense of hearing is poorly developed; hence the former will experience a feeling of happiness, while the latter will remain insensible, for one understands and perceives what makes no impression on the other. It is the same with regard to the joys of spirits, which depend upon their ability to sense them. The spiritual world has splendours everywhere, harmonies and sensations which the lower spirits, still subject to the influence of matter, do not get a glimpse of, and which are accessible only to purified spirits.

The progress of spirits is the fruit of their own labour. However, since they are free, they work for their advancement with more or less diligence, with more or less idleness, according to their will. Thus they hasten or retard their progress, and consequently their happiness. While some advance rapidly, others remain for long centuries in the lower ranks. They are, therefore, the architects of their own situation, whether happy or unhappy, in accordance with the words of Christ: ‘To each according to his works’. The spirit who delays can only complain of himself, just as he who progresses possesses the sole merit of his own efforts, and therefore appreciates more highly the happiness he has gained.