Having shown that moral actions are mental ones, and adduced evidence to prove that mental actions are largely subject to scientific principles;--it follows as a necessary consequence, that moral actions also largely obey those principles, and I need not repeat that evidence. The extension of scientific knowledge conduces in a very general way to moral progress, by diffusing the "scientific spirit," increasing our love of truth, facilitating the attainment of greater certainty and accuracy, enabling us to more perfectly avoid error, reducing our ignorance, dispelling superstition, inculcating obedience to law, diminishing difference of opinion and thereby lessening strife, conducing to humility, to greater economy of means, to increased cleanliness, &c, &c. Scientific research also, by disclosing to man his true position in nature, enables him to act in harmony therewith, and thus increase his morality and general happiness. Knowledge is as free as the air, once diffused it becomes impressed upon the brains of men and cannot be easily destroyed or restrained; and the greatest moral effects of science are cosmopolitan ones. Inventions based upon new scientific truths are gradually {122} breaking down the barriers between the various nations of the Earth, and infusing common interests amongst all mankind. Nothing is uniting the sympathies of different nations, increasing the friendly feelings between them, and diminishing the probability of war, more than the increasing facilities of communication brought about in a great measure by the developments of science and art; more particularly by ocean steam navigation, rapid postal communication and the telegraph, (see p. 51). At the present time there are about six Atlantic telegraph cables in use, and an almost daily service of passenger steam ships across that ocean. The use of inventions based upon scientific discovery has aided moral progress in various ways. All inventions are made with the object of supplying some real or supposed want, and nearly everything which supplies a common want, conduces to contentment and happiness and the general progress of mankind. No one can possibly measure or estimate the advantage of the inventions of writing and printing, in helping men to avoid quarrels, to settle differences of opinion, to sympathise with suffering, to give advice: &c. Similar moral functions are also performed by the electric telegraph, and a few specimens of some of the messages sent through the wire would clearly illustrate this fact. Great moral progress has also resulted from cheap daily intelligence, collected largely with the aid of the telegraph; and of cheap books produced by means of the steam engine. It is estimated that 250 millions {123} of copies of newspapers are yearly published in Great Britain. The Bible and Religious Tract Societies could hardly have existed had not the properties of the ingredients of ink been discovered. The present