The simplicity of the human soul and
the questions to which it gives rise

Introduction

429. If human souls were bereft of bodies, no one would doubt their spirituality. Their union with the body is the cause of doubts about their simplicity and spirituality in minds that have not succeeded in coming to solid knowledge about the nature of this union. This is why I have used the previous book to explore it.
This important truth, the subject of so many disputes, was disentangled from the dross which impelled truly learned but somewhat impatient men to conclude without more ado that this union was an impenetrable mystery. As a result, the apparent difficulties of materialists have been overcome, and I have been able to support spirituality without plunging into errors of a very different kind that caused the fall of upholders of the spirit in their attempt to explain their truly noble and consoling dogma.

Pre-established harmony, occasional causes, Berkeley's idealism, the Aristotelian act of the body, subtle bodies bordering on supposed tenuousness of spirit are the principal systems undertaking to explain the animal phenomena which appear in matter. All are errors giving rise to very dangerous consequences. The next step therefore is to harvest the fruit of the teachings developed in the preceding book and consider explicitly this essential characteristic of the soul called simplicity or spirituality. This is linked with extremely important questions such as the origin or generation or multiplication of the soul (the problem goes under various names) whose difficulty lies solely in conceiving how the soul, which is essentially spiritual and simple, acts in the body and receives action from the body, and is subject to experiences apparently similar to those undergone by matter, although there is only analogy or proportion between them. I shall begin by explaining at greater length than previously the direct proofs of the simplicity of the human soul.