1
general::
Phrase(s): horse sense
Fig. common sense; practical thinking. • Bob is no scholar but he has a lot of horse sense. • Horse sense tells me I should not be involved in that project.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Sound practical sense, as in She's got too much horse sense to believe his story. The exact allusion in this term, which dates from the mid-1800s, is disputed, since some regard horses as rather stupid. However, they tended to be viewed more positively in the American West, where the term originated.
American Heritage Idioms