65. The instance here chosen is not the most favourable for the experimental philosopher. He might perhaps hope to gain more knowledge by applying the best microscope to a regular crystal or to an organised substance. And it is impossible not to regret that the great discovery of the solar microscope has been either so imperfectly turned to account by philosophers, or has disappointed their hopes of exhibiting the mechanism of nature with the distinctness they require. But there is evidently a fundamental limitation of physical science, arising from those of the bodily senses and of muscular motions. The nicest instruments must be constructed and directed by the human hand; the range of the finest glasses must have a limit not only in their own natural structure but in that of the human eye. But no theory in science will be acknowledged to deserve any regard, except as it is drawn immediately, and by an exclusive process, from the phænomena which our senses report to us. Thus, the regular observation of definite proportions in chemical combination has suggested the atomic theory; and even this has been sceptically accepted by our cautious school of philosophy. If we are ever to go farther into the molecular analysis of substances, it must be through the means and upon the authority of new discoveries exhibited to our senses in experiment. But the existing powers of exhibiting or compelling nature by instruments, vast as they appear to us, and wonderful as has been their efficacy in many respects, have done little for many years past in diminishing the number of substances reputed to be simple; and with strong reasons to suspect that some of these, at least, yield to the crucible of nature, our electric batteries have up to this hour played innocuously round their heads. 66. Bacon has thrown out, once or twice, a hint at a single principle, a summary law of nature, as if all subordinate causes resolved themselves into one great process, according to which God works his will in the universe: Opus quod operatur Deus a principio usque ad finem. The natural tendency towards simplification, and what we consider as harmony, in our philosophical systems, which Lord Bacon himself reckons among the _idola tribûs_, the fallacies incident to the species, has led some to favour this unity of physical law. Impact and gravity have each had their supporters. But we are as yet at a great distance from establishing such a generalization, nor does it appear by any means probable that it will ever assume any simple form. |Inductive logic; whether confined to physics.|