Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them. …'Tis not contrary … - David Hume

Tis not unreasonable for me to prefer the destruction of the whole world to the scratching of my finger.

Morality is a subject that interests us above all others: We fancy the peace of society to be at stake in every decision concerning it; and 'tis evident, that this concern must make our speculations appear more real and solid, than where the subject is, in a great measure, indifferent to us. What affects us, we conclude can never be a chimera; and as our passion is engag'd on the one side or the other, we naturally think that the question lies within human comprehension; which, in other cases of this nature, we are apt to entertain some doubt of. Without this advantage I never should have ventur'd upon a third volume of such abstruse philosophy, in an age, wherein the greatest part of men seem agreed to convert reading into an amusement, and to reject every thing that requires any considerable degree of attention to be comprehended.

In such a chain, too, or succession of objects, each part is caused by that which preceded it, and causes that which succeeds it. Where then is the difficulty? But the WHOLE, you say, wants a cause. I answer, that the uniting of these parts into a whole, like the uniting of several distinct countries into one kingdom, or several distinct members into one body, is performed merely by an arbitrary act of the mind, and has no influence on the nature of things. Did I show you the particular causes of each individual in a collection of twenty particles of matter, I should think it very unreasonable, should you afterwards ask me, what was the cause of the whole twenty. This is sufficiently explained in explaining the cause of the parts.

We must therefore glean up our experiments in this science from a cautious observation of human life, and take them as they appear in the common course of the world, by men’s behaviour in company, in affairs, and in their pleasures. Where experiments of this kind are judiciously collected and compared, we may hope to establish on them a science, which will not be inferior in certainty, and will be much superior in utility to any other of human comprehension.