We cannot be sure that the existing Jain scriptures present these doctrines in their original form, but the full acceptance of metempsychosis, the animistic belief that plants, particles of earth and water have souls and the materialistic phraseology (from which the widely different speculations of the Upanishads are by no means free) agree with what we know of Indian thought about 550 B.C. Jainism like Buddhism ignores the efficacy of ceremonies and the powers of priests, but it bears even fewer signs than Buddhism of being in its origin a protestant or hostile movement. The intellectual atmosphere seems other than that of the Upanishads, but it is very nearly that of the Sânkhya philosophy, which also recognizes an infinity of individual souls radically distinct from matter and capable of attaining bliss only by isolation from matter. Of the origin of that important school we know nothing, but it differs from Jainism chiefly in the greater elaboration of its psychological and evolutionary theories and in the elimination of some materialistic ideas. Possibly the same region and climate of opinion gave birth to two doctrines, one simple and practical, inasmuch as it found its principal expression in a religious order, the other more intellectual and scholastic and, at least in the form in which we read it, later[259]. Right conduct is based on the five vows taken by every Jain ascetic, (1) not to kill, (2) not to speak untruth, (3) to take nothing that is not given, (4) to observe chastity, (5) to renounce all pleasure in external objects. These vows receive an extensive and strict interpretation by means of five explanatory clauses applicable to each and to be construed with reference to deed, word, and thought, to acting, commanding and consenting. Thus the vow not to kill forbids not only the destruction of the smallest insect but also all speech or thought which could bring about a quarrel, and the doing, causing or permitting of any action which could even inadvertently injure living beings, such as carelessness in walking. Naturally such rules can be kept only by an ascetic, and in addition to them asceticism is expressly enjoined. It is either internal or external. The former takes such forms as repentance, humility, meditation and the suppression of all desires: the latter comprises various forms of self-denial, culminating in death by starvation. This form of religious suicide is prescribed for those who have undergone twelve years' penance and are ripe for Nirvana[260] but it is wrong if adopted as a means of shortening austerities. Numerous inscriptions record such deaths and the head-teachers of the Digambaras are said still to leave the world in this way.