If a double relation, therefore, of impressions and ideas is able to produce a transition from one to the other, much more an identity of impressions with a relation of ideas. Accordingly we find, that when we either love or hate any person, the passions seldom continue within their first bounds; but extend themselves towards all the contiguous objects, and comprehend the friends and relations of him we love or hate.
For instance:
Nothing is more natural than to bear a kindness to one brother on account of our friendship for another, without any farther examination of his character. A quarrel with one person gives us a hatred for the whole family, tho’ entirely innocent of that, which displeases us. Instances of this kind are everywhere to be met with.
“Instances of this kind are everywhere to be met with”: again, a regression to the infinite, in Hume’s favourite argumentative style. Such situations happen so frequently in everyday life, Hume knows that everyone will see oneself in them: the passions often overflow from their main object (compassion spreads around the loved one, aversion contaminates the surroundings of a despised person).
This observation on the passions reveals one thing: they tend to go out of bounds. Reason has no grip on the passions (or so little). The passions, by how they operate, have a much wider impact on one’s temperament and on their kindness towards others (a chef in anger will blame without shame his cooks for faults they did not commit, simply by extension of the unpleasant passion).
The passions have no limits, or these cannot be observed by a reasonable mind.