A spiritual soul cannot be corrupted, since it
possesses no matter; it cannot be disintegrated, since it has no substantial
parts; it cannot lose its individual unity, since it is self-subsisting, nor
its internal energy, since it contains within itself all the sources of its
energies. The human soul cannot die. Once it exists, it cannot disappear; it
will necessarily exist forever, endure without end. Thus philosophic reason is
able to prove the immortality of the human soul in a demonstrative manner.
--Jacques Maritain
