We speak not strictly and philosophically when we talk of the combat of passion and of reason. Reason is, and ought only to be the slave of the passi… - David Hume

Reason is, and ought only to be the slave of the passions.

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.

The passion for philosophy, like that for religion, involves a
certain danger. Although it aims to correct our behaviour
and wipe out our vices, it may — through not being handled
properly — end up merely encouraging us to carry on in
directions that we’re already naturally inclined to follow.

As every enquiry, which regards religion, is of the utmost importance, there are two questions in particular, which challenge our attention, to wit, that concerning its foundation in reason, and that concerning its origin in human nature. Happily, the first question, which is the most important, admits of the most obvious, at least, the clearest, solution. The whole frame of nature bespeaks an intelligent author; and no rational enquirer can, after serious reflection, suspend his belief a moment with regard to the primary principles of genuine Theism and Religion. But the other question, concerning the origin of religion in human nature, is exposed to some more difficulty. The belief of invisible, intelligent power has been very generally diffused over the human race, in all places and in all ages; but it has neither perhaps been so universal as to admit of no exception, nor has it been, in any degree, uniform in the ideas, which it has suggested. Some nations have been discovered, who entertained no sentiments of Religion, if travellers and historians may be credited; and no two nations, and scarce any two men, have ever agreed precisely in the same sentiments.

There is no craving or demand of the human mind more constant and insatiable than that for exercise and employment, and this desire seems the foundation of most of our passions and pursuits.