Gravely reflecting upon persons

CAESAR once, seeing some wealthy strangers at Rome, carrying up and down with them in their arms and bosoms young puppy-dogs and monkeys, embracing and making much of them, took occasion not unnaturally to ask whether the women in their country were not used to bear children; by that prince-like reprimand gravely reflecting upon persons who spend and lavish upon brute beasts that affection and kindness which nature has implanted in us to be bestowed on those of our own kind. With like reason may we blame those who misuse that love of inquiry and observation which nature has implanted in our souls, by expending it on objects unworthy of the attention either of their eyes or their ears, while they disregard such as are excellent in themselves, and would do them good.
http://classics.mit.edu/Plutarch/pericles.html
In the above passage, what does gravely reflecting upon persons mean?