A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v2.c35.103

v2.c35.103

The Scientific Methods already noticed, the Joint Method of Difference (the Panchakárani), and the Joint Method of Agreement (Vyáptigraha with Upádhisanká-nirasa and Tarka), are not the only methods of ascertaining causality or concomitance, or establishing a theory (सिद्धान्त); nor are these Methods always practicable. Very often, we reach the explanation of a fact (उपपत्ति) by means of a Hypothesis (कल्पना) properly tested and verified (निर्णीत). A legitimate Hypothesis must satisfy the following conditions:—(1) the hypothesis must explain the facts (दृष्टसिद्धि, or उपपत्ति); (2) the hypothesis must not be in conflict with any observed facts or established generalisations (दृष्टसिद्धये हि दृष्टं कल्प्यते, न दृष्टविघाताय—Jayanta, Nyáya-Manjari, Ahnika 1); (3) no unobserved agent must be assumed, where it is possible to explain the facts satisfactorily by observed agencies (यदि दृष्टमन्तरेण दृष्टं न सिद्ध्यति काममदृष्टं कल्प्यताम्, अन्यथाऽपि तदुपपत्तौ किं तदुपकल्पनेन, ibid); (4) when two rival hypotheses are in the field, a crucial fact or test (विनिगम, ratio sufficiens) is necessary; the absence of such a test (विनिगमनाविरह) is fatal to the establishment of either, (5) of two rival hypotheses, the simpler, *i.e.*, that which assumes less, is to be preferred (*ceteris paribus*) (कल्पनालाघव versus कल्पनागौरव); (6) of two rival hypotheses, that which is immediate or relevant to the subject-matter is to be preferred to that which is alien or remote (प्रथमोपस्थितत्व); (7) a hypothesis that satisfies the above conditions must be capable of verification (निर्णय) before it can be established as a theory (सिद्धान्त). The process of verification of a hypothesis consists in showing that it can be deduced as a corollary from (or is involved by implication in) some more general proposition which is already well-established (cf. Vatsyayana’s exposition and illustration of Verification, निर्णय,—including both the Deductive Method and Colligation).